Peptides capable of reactivating p53 mutants

ABSTRACT

The invention provides peptides that can reactivate p53 mutants efficiently and specifically, as well as methods that allow the identification, selection and isolation of such peptides, in a precise, cost and time effective manner. In particular, there are provided mutant p53 reactivating peptides that can restore the native wild type p53 folding, and hence the tumor suppressor activity, to the mutant p53 protein. Such peptides are useful for treating various conditions and diseases in which p53 is mutated.

RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No. 16/451,081 filed on Jun. 25, 2019, which is a division of U.S. patent application Ser. No. 15/796,811 filed on Oct. 29, 2017, now U.S. Pat. No. 10,336,789, which is a division of U.S. patent application Ser. No. 15/015,208 filed on Feb. 4, 2016, now U.S. Pat. No. 9,856,289, which is a Continuation In Part of PCT Patent Application No. PCT/IB2014/063777 having International Filing Date of Aug. 7, 2014, which claims the benefit of priority under 35 USC § 119(e) of U.S. Provisional Patent Application No. 61/862,977 filed on Aug. 7, 2013. The contents of the above applications are all incorporated by reference as if fully set forth herein in their entirety.

SEQUENCE LISTING STATEMENT

The ASCII file, entitled 79778SequenceListing.txt, created on Nov. 28, 2019, comprising 91,930 bytes, submitted concurrently with the filing of this application is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to peptides capable of reactivating mutant p53 proteins, and use thereof in therapy.

BACKGROUND OF THE INVENTION

Cancer is a leading cause of death in developed countries, and as the average age of the population continues to rise, so do the numbers of diagnosed cases and economic implications. Cancer is not a single disease, but rather a group of more than 200 diseases characterized by uncontrolled growth and spread of abnormal cells. Cancer is a highly heterogeneous disease with major molecular differences in the expression and distribution of tumor cell surface markers even among patients with the same type and grade of cancer. Moreover, cellular mutations tend to accumulate as cancer progresses, further increasing tumor heterogeneity. Most tumor cells exhibit genomic instability with an increased expression of oncogenes and inactivation of tumor suppressor genes.

The p53 gene is considered to be the most important tumor suppressor gene, which acts as a major barrier against cancer progression. The p53 protein responds to various types of cellular stress, and triggers cell cycle arrest, apoptosis, or senescence (Levine, J. A., p53, the cellular gatekeeper for growth and division. Cell, 1997. 88: p. 323-331). This is achieved by transcriptional transactivation of specific target genes carrying p53 DNA binding motifs. It is widely agreed that the p53 pathway is impaired in almost all human cancers. Mutation of p53 is viewed as a critical step in malignant transformation process and over 50% of cancer cases carry mutations in their p53 genes. Most of these mutations are missense point mutations that target the DNA-binding core domain (DBD) of p53, thereby abolishing specific DNA binding of p53 to its target site. These mutations prevent p53-dependent transcription and consequently p53-mediated tumor suppression. The exceptionally high frequency of p53 mutations in human tumors of diverse types makes p53 unique among genes involved in tumor development, rendering mutated p53 (Mut-p53) an attractive target for novel cancer therapies.

Structural studies have revealed that the tumor-derived missense mutations in the DBD of p53 produce a common effect: destabilization of DBD folding at physiological temperature (Joerger, A. C., M. D. Allen, and A. R. Fersht, Crystal structure of a superstable mutant of human p53 core domain. Insights into the mechanism of rescuing oncogenic mutations. J Biol Chem, 2004. 279(2): p. 1291-6). This destabilization may be reversible, since some mutants can revert to wild-type conformation and bind DNA at reduced temperatures. Thus, most mutations of p53 destabilize p53 protein folding, causing partial denaturation at physiological temperature.

Mutant p53 proteins accumulate at high levels in tumor cells, mainly due to their inability to upregulate the expression of p53's own destructor Mdm2. Moreover, many p53 activating stress signals (like hypoxia, genomic instability and oncogene expression) are constitutively induced in cancer cells. Therefore, reactivation of Mut-p53 is expected to exert major anti-tumor effects. Furthermore, it has been shown in a mouse model that restoration of p53 functions is well tolerated in normal tissues and produces no visible toxic effects (Ventura, A., et al., Restoration of p53 function leads to tumour regression in vivo. Nature, 2007. 445(7128): p. 661-5).

p53 has evolved to be dynamic and conformationally unstable. The lack of a rigid structure of the p53 protein may result in a number of p53 conformers displaying different activity, depending on the type of stress and cellular context. In a simplified model, p53 can assume either a wild type, active conformation or a mutant, misfolded, inactive conformation. The two conformational states of p53 can be distinguished by two specific monoclonal antibodies, PAb240 and PAb1620 (Wang, P. L., F. Salt, and G. Winter, The ‘wild type’ conformation of p53: epitope mapping using hybrid proteins. Oncogene, 2001. 20(18): p. 2318-24). PAb240 binds to residues 212-217 in the DBD of p53. This region is inaccessible to the antibody (Ab) in the wild type (WT) conformation. However, in denatured or mutant p53, it is exposed (Vojtesek, B., et al., Conformational changes in p53 analyzed using new antibodies to the core DNA binding domain of the protein. Oncogene, 1995. 10(2): p. 389-93). PAb1620 recognizes a conformational, nonlinear epitope in the DBD, composed of two distinct regions of p53 and including residues R156, L206, R209 and N210 (Cook, A. and J. Milner, Evidence for allosteric variants of wild-type p53, a tumor suppressor protein. Br J Cancer, 1990. 61(4): p. 548-52). In the WT conformation the protein is folded in a way that holds the loops in close proximity to each other (Ravera, M. W., et al., Identification of an allosteric binding site on the transcription factor p53 using a phage-displayed peptide library. Oncogene, 1998. 16(15): p. 1993-9), forming the complete epitope recognized by PAb1620. When p53 protein is misfolded (as a result of mutation, temperature, denaturation or the like), these two loops move farther away, the epitope is destroyed and therefore the mutant conformation is PAb1620 negative. It has been shown that p53 is a conformationally flexible protein. However, the defect in folding in such mutants is not irreversible: some p53 mutants maintain residual DNA-binding ability, mutants that fail to bind DNA at 37° C. can bind at sub-physiological temperatures (32° C. or 25° C.), and activate transcription from a p53-responsive promoter at 26° C. In addition, the isolated DBD's of mutant proteins R245S, R282W, V143A and others were shown to have residual (30-60%) DNA-binding activity at 20° C.

Structural studies show that the extent of misfolding differs among mutants; however, there is no defined alternative fold but rather a partial denaturation. This suggests that a “small molecule’ approach to reverse the effect of p53 mutation on folding could be applicable to a wide range of mutant forms. Another important prediction from structural studies is that a ligand that binds to the properly folded fraction of the protein is expected to shift the equilibrium towards the native fold according to the law of mass action.

p53 was first identified as a cellular protein interacting with the SV40 large T antigen (LT). The interface area between LT and p53 is large: a total of 23 LT residues and 19 p53 residues are either buried in this interface or are found to directly participate in the interactions between these two molecules. p53/DNA interaction residues are adjacent and overlapping with the p53/LT interface. The binding of LT to these p53 residues can effectively shield the entire DNA-binding surface of p53, including the three most commonly mutated p53 residues in cancer: R273, R248, and G245. This inhibits transactivation of p53-dependent promoters. Since the p53/LT interface involves several different p53 regions and loops, the p53 protein has to be folded correctly to align amino acids in the correct location and orientation to form the binding context to LT. Therefore, p53 binding to LT can serve as a marker to the p53 conformational state.

Several correctional approaches were attempted in the p53 conformation field. Proof of principle for conformation stabilizing peptides was provided by Friedler and colleagues (Friedler, A., et al., A peptide that binds and stabilizes p53 core domain: chaperone strategy for rescue of oncogenic mutants. Proc. Natl. Acad. Sci. USA, 2002. 99(2): p. 937-42). A nine-residue peptide, CDB3, was designed based on the crystal structure of the complex between the p53 DBD and ASPP (Samuels-Lev, Y., et al., ASPP proteins specifically stimulate the apoptotic function of p53. Mol. Cell, 2001. 8(4): p. 781-94). This peptide was shown to bind Mut-p53 and act as a chaperone, shifting equilibrium towards the WT conformation, as indicated by increased reactivity to PAb1620. However, the biological effects of CDB3 (Issaeva, N., et al., Rescue of mutants of the tumor suppressor p53 in cancer cells by a designed peptide. Proc. Natl. Acad. Sci. USA, 2003. 100(23): p. 13303-7) are only partial since the conformation of the Mut-p53/CDB3 complex is in an intermediate state between WT and mutant.

Small molecule compounds targeting Mut-p53 have been identified using either protein-based or cell-based assays (Peng, Y., et al., Rescue of mutant p53 transcription function by ellipticine. Oncogene, 2003. 22(29): p. 4478-87). CP-31398 was identified by screening for molecules that protect the isolated p53 DBD from thermal denaturation, as assessed by maintenance of PAb1620 reactivity upon protein heating (Foster, B. A., et al., Pharmacological rescue of mutant p53 conformation and function. Science, 1999. 286(5449): p. 2507-10). The mechanism of action of CP-31398 remains unclear. NMR studies failed to detect any binding of CP-31398 to the p53 DBD (Rippin, T. M., et al., Characterization of the p53-rescue drug CP-31398 in vitro and in living cells. Oncogene, 2002. 21(14): p. 2119-29). CP-31398 affects gene expression and induces cell death both in a p53-dependent and independent manner. Thus, it appears that CP-3138 has other cellular targets than p53 that may account for its cellular toxicity.

Two other small molecules that rescue p53 function in living cancer cells, PRIMA-1 and MIRA-1, were discovered by using cell-based screening assays. PRIMA-1 and MIRA-1 have similar activity profiles (Bykov, V. J., et al., Reactivation of mutant p53 and induction of apoptosis in human tumor cells by maleimide analogs. J Biol Chem, 2005. 280(34): p. 30384-91), but are structurally unrelated. So far, direct binding to Mut-p53 has not been demonstrated. It seems that the mechanism may involve the JNK pathway.

In the field of anti-cancer drug discovery and design, two different and at times complementary, strategies may be employed. Rational design, which uses biological, mathematical or computational tools to design molecules for a certain purpose, has been used in the case of CDB3. However, since the interactions between different proteins and their environment are complex, this is extremely difficult and often yields molecules with a modest biological impact. The second strategy is high throughput screening of molecule libraries, to isolate compounds with the best traits. Such screening can employ either chemical, small molecule libraries or peptide libraries. Most drugs available to date are small molecules because of their ability to cross cell membranes. Chemical libraries usually consistent of 10⁴-10⁵ different compounds; screening such a library requires functional assessment of individual molecules, making it impractical for a small laboratory since it calls for large investments in robotics and/or manpower. Peptide display libraries are much larger. Selection of peptides is based on binding of peptides (and hence the phage), to an immobilized target, elution and amplification and then identification by sequencing.

In the phage display procedure, enrichment of phages that present a peptide is achieved by affinity selection of a phage library on immobilized target. In this “panning” process, binding phages are captured whereas nonbinding ones are washed off. In the next step, the bound phages are eluted and amplified by reinfection of E. coli cells. The amplified phage population can, in turn, be subjected to the next round of panning. The selection from phage display libraries is a cyclic process of selective enrichment and amplification. After several rounds of selection, phages are diluted in a way that allows isolation of individual phage clones. Individual clones are then picked, cultivated in E-coli, phage DNA is extracted and then sent to sequencing. Recently developed next-generation sequencing technologies are greatly increasing the effectiveness of phage display, allowing analysis of the entire selected peptide repertoire, with fewer selection rounds performed.

Phage display offers several important advantages over other screening methods; the major advantage of phage display is the diversity of sequences that can be represented, enabling finding molecules with very high affinity and biological effect. Once a consensus peptide sequence is found, it can be further improved by either directed evolution techniques or rational design.

Nevertheless, there remains an unmet need in the art for agents that can reactivate p53 mutant proteins efficiently and specifically. Such specific and efficient agents can further be used as an effective mean for treating various conditions in which p53 is mutated, in particular, by restoring the native folding and activity of the mutant p53 proteins.

SUMMARY OF THE INVENTION

The present invention provides highly potent peptides and modified peptide agents that can efficiently reactivate p53 conformational mutants, ideally by changing the mutant p53 proteins conformation and/or activity to resemble that of a wild type, functional p53 protein. The present invention thus provides peptides and their use in treating mutant p53 related conditions, where activation of present yet conformationally defective p53 proteins may be beneficial.

The present invention is based on the suprising identification of highly potent peptide and peptide-based agents that can efficiently reactivate p53 conformational mutants, more efficiently than previously known peptides identified for this use. The present invention thus provides, in an aspect, a recombinant or synthetic peptide consisting of the amino-acid sequence set forth in any one of SEQ ID NOs:321-286.

The present invention further provides, in another aspect, a recombinant or synthetic peptide comprising the amino-acid sequence set forth in any one of SEQ ID NOs:321-286, wherein said peptide at least partially reactivates a mutant p53 protein.

The present invention further provides, in yet another aspect, a recombinant or synthetic peptide comprising the amino-acid sequence set forth in any one of SEQ ID NOs: 302-321, 312-321 and 316-321, wherein said peptide at least partially reactivates a mutant p53 protein. Each possibility represents a separate embodiment of the invention.

The present invention further provides, in yet another aspect, a recombinant or synthetic peptide comprising the amino-acid sequence set forth in any one of SEQ ID NOs: 316-321, wherein said peptide at least partially reactivates a mutant p53 protein. Each possibility represents a separate embodiment of the invention.

The present invention further provides, in yet another aspect, a recombinant or synthetic peptide comprising a consensus motif of the amino-acid sequence set forth in any one of SEQ ID NOs: 314, 268, 282, 328, 376, 298, 377, 378, 253, 20, 379, 302, 275, 380, 273, 381, 280 or 382, wherein said peptide at least partially reactivates a mutant p53 protein. According to a specific embodiment the consensus motif is as set forth in SEQ ID NO: 314.

In certain embodiments, the peptide consists of the amino-acid sequence set forth in any one of SEQ ID NO:321, SEQ ID NO:314, SEQ ID NO:313, SEQ ID NO:310 or SEQ ID NO:307. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above consists the amino-acid sequence set forth in any one of SEQ ID NOs:321-302. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above consists the amino-acid sequence set forth in any one of SEQ ID NOs:321-312. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above consists the amino-acid sequence set forth in any one of SEQ ID NOs:321-316. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above consists the amino-acid sequence set forth in any one of SEQ ID NOs: 302-321, 312-321 and 316-321, wherein said peptide at least partially reactivates a mutant p53 protein. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide described above consists the amino-acid sequence set forth in any one of SEQ ID NOs: 302-321, 312-321 and 316-321, wherein said peptide at least partially reactivates a mutant p53 protein. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide comprises of the amino-acid sequence set forth in any one of SEQ ID NO:321, SEQ ID NO:314, SEQ ID NO:313, SEQ ID NO:310 or SEQ ID NO:307. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs:321-302. In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs:321-312. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs:321-316. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs: 307, 310, 313, 314 and 321. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs: 302-321, 312-321 and 316-321. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide is conjugated to at least one cell penetrating moiety (lipid and/or proteinaceous). The cell penetrating moiety may be conjugated N-terminally to the peptide, C terminally to the peptide, anywhere in the backbone of the peptide or to a combination of same. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the cell penetrating moiety is selected from the group consisting of a fatty acid moiety, a protennacious moiety and a combination of same.

In certain embodiments, the peptide is conjugated to at least one fatty acid moiety. In certain embodiments, the fatty acid is selected from the group consisting of myristic acid, lauric acid, palmitic acid and stearic acid. Each possibility represents a separate embodiment of the invention. In certain embodiments, the fatty acid is a myristoyl fatty acid.

In certain embodiments, the peptide is conjugated to at least one proteinacious moiety. In certain embodiments, the proteinaceous moiety is a poly-cationic amino acid e.g., poly-Lysine and/or poly-Arginine e.g., having 2-15 arginine residues e.g., conjugated to at least one end of the peptide (N and/or C). Each possibility represents a separate embodiment of the invention. According to a specific embodiment, the protenaceious moiety comprises at least one positively charged amino acid at either of the peptide's termini i.e., N and/or C terminus. Each possibility represents a separate embodiment of the invention. For instance, at least one positively charged (e.g., R, RR, RRR) can be conjugated to the N-terminus or C-terminus of SEQ ID NO: 314. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide at least partially changes the conformation of said mutant p53 protein to a conformation of a wild-type (WT) p53 protein.

In certain embodiments, the peptide at least partially changes the conformation of said mutant p53 protein such that said mutant p53 protein is recognized by a monoclonal antibody directed against a WT p53 protein. In certain embodiments, the monoclonal antibody is Ab1620.

In certain embodiments, the peptide at least partially restores the activity of said mutant p53 protein to the activity of a WT p53 protein.

In certain embodiments, the activity is reducing viability of cells expressing said mutant p53 protein. In certain embodiments, the activity is promoting apoptosis of cells expressing said mutant p53 protein. In certain embodiments, the activity is activating pro-apoptotic genes of cells expressing said mutant p53 protein. In certain embodiments, the pro-apoptotic genes are selected from the group consisting of CD95, Bax, DR4, DR5, PUMA, NOXA, Bid, 53AIP1 and PERP. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the activity is binding to a p53 consensus DNA binding element in cells expressing said mutant p53 protein. In certain embodiments, the consensus DNA binding element comprises the amino acid sequence set forth in SEQ ID NO:339.

In certain embodiments, the binding results in at least partial activation of an endogenous p53 target gene. In certain embodiments, the endogenous target gene is selected from the group consisting of p21, MDM2 and PUMA. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the mutant p53 protein is of a different conformation than a WT p53 protein. In certain embodiments, the mutant p53 protein is at least partly inactive compared to a WT p53 protein.

In certain embodiments, the mutant p53 protein is not recognized by a monoclonal antibody directed against a WT p53 protein. In certain embodiments, the mutant p53 protein, upon binding to said peptide, is recognized by a monoclonal antibody directed against a WT p53 protein. In certain embodiments, the monoclonal antibody is Ab1620.

In certain embodiments, the mutant p53 protein comprises a mutation selected from the group consisting of R175H, V143A, R249S, R273H, R280K, P309S, P151S, P151H, C176S, C176F, H179L, Q192R, R213Q, Y220C, Y220D, R245S, R282W, D281G, S241F, C242R, R248Q, R248W, D281G, R273C and V274F. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide comprises the consensus motif set forth in SEQ ID NO:314. In certain embodiments, the peptide comprises the amino-acid sequence set forth in any one of SEQ ID NO:321, SEQ ID NO:314, SEQ ID NO:313, SEQ ID NO:310 or SEQ ID NO:307. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide consists of the amino-acid sequence set forth in any one of SEQ ID NO:321, SEQ ID NO:314, SEQ ID NO:313, SEQ ID NO:310 or SEQ ID NO:307. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide comprises the amino-acid sequence set forth in any one of SEQ ID NOs:268, 282, 328, 376, 298, 377, 378, 253, 20, 379, 302, 275, 380, 273, 381, 280 or 382. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide comprises the amino-acid sequence set forth in any one of SEQ ID NOs:379, 302, 275, 380, 273, 381, 280 or 382. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide comprises the amino-acid sequence set forth in any one of SEQ ID NOs: SEQ ID NOs:302, 275, 380, 273, 381, 280 or 382. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs: 307, 310, 313, 314 and 321. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs: 302-321, 312-321 and 316-321. Each possibility represents a separate embodiment of the invention.

The present invention further provides, in another aspect, an expression vector, capable of expressing the peptides described above.

The present invention further provides, in yet another aspect, a pharmaceutical composition, comprising the peptides described above.

The present invention further provides, in yet another aspect, a pharmaceutical composition, comprising the expression vector described above.

In an aspect, the pharmaceutical compositions described above are for use in treating a disease, disorder or condition associated with a mutant p53 protein.

In some embodiments, the disease is cancer. In some embodiments, the cancer is selected from the group consisting of breast cancer, colon cancer and lung cancer. Each possibility represents a separate embodiment of the invention.

In some embodiments, the cells of the cancer express the mutant p53 protein.

The present invention further provides, in another aspect, a method of treating a disease, disorder or condition associated with a mutant p53 protein, comprising the step of administering a therapeutically effective amount of the pharmaceutical compositions described above to a subject in need thereof, thereby treating said disease, disorder or condition.

The present invention further provides, in yet another aspect, a kit comprising the pharmaceutical compositions described above.

In an aspect, the kit described above is for use in treating a disease, disorder or condition associated with a mutant p53 protein.

Other objects, features and advantages of the present invention will become clear from the following description and drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a block diagram of steps in a screening method, which provides for selection of binding partners (such as peptides), in a non-direct way, through their effect on conformation or structure of a target molecule.

FIG. 1B is a schematic drawing of a method of identification, screening and selection of mutant p53 reactivating peptides. The method comprises alternating various selection strategies, at increasing stringencies, to screen and identify mutant p53 reactivating peptides, by utilizing a phage display method. Strategy A (left): selection according to conformation: selection of peptides expressed and presented by a phage, which can bind a mutant p53 protein (for example, R175H Mut-p53). The Mut-p53 protein is bound to a specific p53 antibody (for example, PAb1620) that is immobilized to a substrate, thereby enabling selection of a bound phage. Strategy B (right): selection according to function: selection of peptides expressed and presented by a phage, which can reactivate a Mut-p53 (for example, R175H Mut-p53), whereby the activation is determined by the ability of the Mut-p53 protein to bind its DNA consensus binding element. The DNA binding element (for example, WT p53-RE) is immobilized to a substrate. A Mut-p53 cannot bind the WT p53-RE, unless it is at least partially reactivated by the reactivating peptide bound thereto. The method may further comprise sequencing (for example, deep sequencing) of the identified peptides to determine their sequences, and optionally identify a consensus sequence for reactivating peptides.

FIG. 2 is a pictogram of a western blot analysis of immunoprecipitation (IP) experiments, in which agarose beads covalently cross-linked to antibodies (PAb1620 or PAb240) or proteins (ASPP2 or Bcl2) were incubate with a WT p53 protein, mutant p53 R175H protein or mutant p53 V143A (each produced from sf9 cells transfected with baculovirus expressing the respective protein) for 3 hours at 4° C. The resultant immunoprecipitate, as well as the supernatant (sup) were subjected to western blot experiments, using an anti p53 (αp53) antibody conjugated to horseradish peroxidase (HRP), to determine the p53 protein level in each sample.

FIG. 3 is a pictograms of western blot analysis of IP experiments, in which beads that were covalently cross linked to PAb1620 or PAb240 antibodies were incubated with WT p53 or mutant p53 R175H for 3 hours at 4° C. with various solutions (A-I and IP buffer). The resultant immunoprecipitate, as well as the supernatant (sup) were subjected to western blot experiments, using an anti p53 (αp53) antibody conjugated to HRP, to determine the p53 protein level in each sample. Solution A—50 mM Tris; solution B—Tris, 150 mM NaCl; solution C—Tris, NaCl, 0.5% Triton; solution D—Tris, 0.5% Glycine; solution E—40 mM Na₄O₇P₂; solution F—400 mM Guanidine-HCl; solution G—800 mM Guanidine-HCl; solution H—1M Urea; solution I—3M Urea; IP—IP Buffer.

FIG. 4 is the sequence of the oligonucleotide used as the binding element for p53 proteins. The oligonucleotide (SEQ ID NO:61) comprises a 5′ biotin label, followed by a HindIII recognition site (underlined), followed by EcoRI recognition site (underlined), followed by a p53 consensus binding element (underlined, p53 binding site is composed of two half sites, each half site binds a dimmer of p53 and together this site forms a complex of DNA and p53 tetramer), followed by two copies of the p53 recognition element of the p21 promoter (underlined). For binding experiments, this oligonucleotide was annealed to a complementary oligonucleotide to form a double stranded (ds) oligonucleotide.

FIG. 5 is a pictograms of western blot analysis of IP experiments, in which beads that were covalently cross-linked to a PAb1620 antibody were incubated with purified mutant p53 R175H in the presence of phage obtained by phage display selection with either full length Mut-p53 R175H (175) or recombinant Mut-p53 R249S (249 DBD), with prior pre-clearing step performed by incubation of the phage pool with PAb1620 beads. Non selected phage (NS) were used as control. Incubation was done for 3 hours at 4° C. Bound p53 in the immunoprecipitate was analyzed by western blot analysis using antibody against p53 (αp53). Non selected phage (NS) were used as control. “In” stands for 10% of the IP input material that was loaded directly on the gel. Immunoprecipitation with the PAb-421 was used as a positive control and as standard for immunoprecipitated p53, since this antibody binds p53 epitope at the C-terminus regardless of p53 protein conformation.

FIG. 6 is a pictograms of western blot analysis of IP experiments, in which streptavidin-coated beads bound either to p53-RE-DNA or control-RE-DNA oligonucleotides labeled with biotin were incubated with purified WT-p53-DBD or mutant p53-R249S-DBD in the presence of phage obtained by phage display selection with Mut-p53 R175H (175), clone 27 (a single clone isolated from the 175 selection, SEQ ID NO:328); pools #69 and #94 selected with WT and Mut-p53 R175H using combinations of SV-40 large T antigen (T-ag) and PAb1620 at alternating selection rounds. Non selected phage (NS) were used as control. Incubation was performed for 3 hours at 4° C. Bound p53 was visualized by western blot analysis using antibody against p53 (αp53).

FIG. 7 is a schematic illustration of several consensus peptide motifs identified as described herein.

FIGS. 8A and 8B are bar graphs, demonstrating representative ELISA experiments of determining the effect of tested peptides on the conformation changes of Mut-p53 in H1299 cells stably overexpressing Mut-p53 (R175H p53), as determined by immunoassay. To measure the conformational effect of the peptides on Mut-p53, a micro-titer plate was coated with either PAb240, PAb1620 or pAb421 (as a positive control and standard for total p53 protein, since the antibody used recognizes both WT and mutant conformations), overnight incubated, washed, blocked, and cell extracts (with or without peptides) were added for an additional 2 hours. After removal of extracts, plates were washed and incubated with the αp53-HRP conjugated Ab for the detection of p53 levels. A TMB (substrate of HRP) assay was performed and optical density was determined at 450 nm. WT p53 served as a positive control for reactivity with PAb1620, and Mut-p53 served as a negative control. The results are presented as the ratio of absorbance between the PAb1620 or PAb240 samples and the control pAb241 sample. MCF7 and H1299-Mut-p53 (ts) A135V (TS) cells were used as positive controls for the WT p53 conformation (1620/240 ratio equals or exceeds 5:1).

FIG. 9 is a bar graph, demonstrating representative ELISA experiments of determining the effect of tested peptides on the DNA binding activity of Mut-p53 in H1299 cells stably overexpressing Mut-p53 (R175H p53). A commercial p53/DNA binding kit (R&D) was used, according to manufacturer instructions. Briefly, 96 well plates were coated with anti-p53 antibody overnight. Cell extracts containing p53 were reacted with an oligonucleotide that contains a p53 consensus binding site, labeled with biotin, in the presence or absence (NT) of test peptides. WT p53 is expected to bind this DNA binding site as well as to the antibody coating the test wells of the plate. Excess p53 and oligos are washed away and streptavidin-HRP is used to quantify the amount of oligos in the well, which is proportional to the DNA bound by p53. TMB assay was performed to determine HRP levels (450 nm). The results are presented as relative absorbance (at 450 nm) (Y-Axis) of each tested sample. MCF7 and the H1299-Mut-p53 (ts) A135V cells serve as positive controls for WT p53.

FIG. 10 is a bar graph depicting representative ELISA experiments to determine the binding of tested peptides to recombinant WT p53 and Mut-p53. A commercial peptide-protein binding kit (TAKARA) was used according to the manufacturer's instructions. Briefly, 96 well plates were coated with peptides for 2 hours. Soluble peptides were added to the corresponding wells to serve as a competition control to confirm the specificity of peptide binding to p53 (+comp). p53-RE DNA oligo was added to other wells (+DNA) to examine whether it affects the binding of peptides to p53. After removal of recombinant protein, plates were washed and incubated with αp53-HRP conjugated Ab for quantification of p53. Finally a TMB (substrate of HRP) assay was performed and optical density was determined at 450 nm. The results are presented as relative absorbance at 450 nm (Y-Axis) of each tested sample. The following αp53 monoclonal antibodies served as internal controls: PAb1801; PAb1620 and PAb240.

FIG. 11 is a bar graph, demonstrating binding of Mut-p53 to promoters of representative p53 target genes in live cells. BT-549 breast cancer cells endogenously expressing mutant p53^(R249S) were treated for 5 hour with a mix of 3 pCAPs—250, 308 and 325. Cells treated with a mix of control peptides (inert peptides) served as a negative control. Cells were fixed with 1% formaldehyde, harvested and DNA was sheared by sonication. DNA cross-linked to p53 was immunoprecipitated using a polyclonal anti-p53 antibody (H47). DNA was purified and binding to the p53 responsive elements of the PUMA, p21, CD95 and MDM2 gene promoters was quantified by qPCR. Results were normalized to input samples that represent total DNA levels. As a negative control, extracts were immunoprecipitated with beads without antibody (beads). A genomic site not containing any p53 binding element served as a negative control (black).

FIG. 12 is a bar graph illustrating the relative luciferase activity (cLuc/gLuc) as measured in the various tested samples. Transient transfection of H1299 p53^(−/−) cells was performed with plasmids expressing WT p53, R175H p53, R249S p53 or empty vector as control, together with TK-RGC-luc, where luciferase expression is under control of a tandem array of multiple p53-responsive elements. 24 hours after transfection, cells were treated with the test peptides. 48 hours after transfection, a sample of the culture medium was taken for bioluminescence measurements.

FIGS. 13A and 13B are bar graphs illustrating the effect of various tested peptides on the viability of cells expressing Mut-p53, as determine by crystal violet assay. WI-38 fibroblasts expressing endogenous WT p53 were infected with retroviruses expressing either mouse Noxa shRNA (WI38-m-Noxa-i) as a nonspecific control or the R175H p53 mutant for stable overexpression of mutant p53 (WI38-175). The cells (WI38-m-Noxa-i or WI38-175) were seeded at 3000 cells per well in 96-well plates. Tested peptides were added to the cells. Different concentrations of etoposide (cytotoxic drug, 4′-Demethyl-epipodophyllotoxin 9-[4,6-O—(R)-ethylidene-beta-D-glucopyranoside], 4′-(dihydrogen phosphate) were used as positive control for cell death and as a standard reference curve to assess the effect of tested peptides. 48 hours after treatment, cells were washed with PBS to exclude dead cells and debris, and cells that remained attached to the plate were stained with crystal-violet for 30 minutes. Crystal violet was removed and cells were washed 4 times with PBS to remove residual crystal violet. Then, the stained cells were dissolved in 10% acetic acid and plates were taken for optical density measurement at 595 nM (optimal for crystal violet). The bar graphs of FIGS. 13A and 13B show the optical density reads at 595 nm, which reflect the number of cells in the plate after treatment, normalized to the non-treated (NT) samples.

FIG. 14 is a bar graph illustrating the effect of tested peptides on activation of Mut-p53 by measuring transactivation of p53 target genes as determined by qRT-PCR. H1299 cells are p53 null and are widely used for p53 research. H1299 cells stably transfected with Mut-p53 (ts) A135V were used. The cells were plated in 12-well dishes, the indicated peptides were added directly to the medium at a concentration of 5 ug/ml, and cells were then either moved to 32° C. or returned to 37° C. 18 hours later cells were harvested, followed by extraction of RNA, cDNA synthesis and real time PCR analysis. The expression level of 3 representative p53 target genes, p21, PUMA and Mdm2, was examined. The bar graphs shown in FIG. 14 illustrate the relative fold induction of transcription of the tested genes in the various samples relative to their transcription level in non-treated cells.

FIGS. 15A and 15B are bar graphs illustrating the effect of the various indicated peptides on the viability of breast cancer cells expressing different Mut-p53 isoforms, as determined by crystal violet assay. FIG. 15A: MDA-MB-231 cells expressing Mut-p53 with a mutation at position 280 of the DBD. FIG. 15B: SKBR3 cells expressing Mut-p53 with mutation at position 175 within the DBD. The bar graphs in FIGS. 15A and 15B show for each tested peptide the optical density reads at 595 nm, reflecting the number of cells in the plate after treatment, normalized to the non-treated (NT) samples.

FIG. 16 is a bar graph illustrating the effect of the indicated peptides on activation of Mut-p53 by measuring transactivation of p53 target genes as determined by qRT-PCR. SKBR3 ShCon cells and SKBR3 Shp53 cells knocked down for p53 expression were used. The cells were plated in 12-well dishes and the indicated peptides were added directly to the medium at a concentration of 5 ug/ml. 18 hours later cells were harvested, followed by qRT-PCR analysis. Expression level of p21, PUMA and Mdm2 was evaluated. FIG. 16 illustrates the relative fold induction of transcription of the tested genes in the various samples relative to their transcription level in non-treated cells. GAPDH mRNA was measured in parallel as a control.

FIGS. 17A, 17B, 17C and 17D illustrate representative experiments performed on ES2 ovarian carcinoma cells expressing Mut-p53 mutated at position 241 within the DBD. In essence, the cells were plated in 6 cm dishes, and the indicated peptides were added directly to the medium at a concentration of 12 ug/ml at the indicated time points. Cells were harvested and an apoptosis assay (FIGS. 17A and 17B) was performed using the Annexin-V staining kit (Roche, REF 11 988 549 001). Non-fixed cells were stained with both anti Annexin FITC conjugated antibody to detect apoptotic cells, and PI (propidium iodide) to stain dead cells, according to the manufacturer's instructions. Stained cells were then analyzed by flow cytometry. A total of 10,000 cells was counted for each sample and divided into four sub populations according to staining intensity; cells negative for both PI and Annexin (−PI, −Annexin) are termed live; cells negative for PI and positive for Annexin (−PI, +Annexin) are going through early stages of apoptosis; cells positive for PI and Annexin (+PI, +Annexin) are dead cells that underwent an apoptotic process; and cells positive for PI and negative for Annexin (+PI, −Annexin) are assumed as dead cells that died by a non-apoptotic process such as necrosis.

FIGS. 18A, 18B and 18C illustrate the in vivo effect of the indicated peptides in a mouse xenograft model. MDA-MB-231 cells expressing endogenous mutant p53 and stably expressing luciferase were injected into the left hip of CD1 nude/nude mice. When tumors reached visible size, bioluminescence (indicative of the number of cancer cells) was measured with the IVIS200 system. The mice were then treated by intra-tumoral injection, three times a week, with a mixture of 3 control peptides that showed no phenotype in vitro (pCAPs 76, 77 and 12; 2 mg of each peptide). 35 days after initiation of treatment, the experiment was terminated. FIG. 18A shows a logarithmic scale graph demonstrating the luciferase readings in each tumor as a function of time after initiation of treatment (peptide injection). FIG. 18B shows live imaging images of mice (7-10), at the beginning of treatment. FIG. 18C shows live imaging images of treated mice (7-9) at day 35, when the experiment was terminated. Mouse 10 had to be sacrificed after 28 days due to large tumor size.

FIGS. 19A, 19B and 19C illustrate the in vivo effect of the indicated peptides in a mouse xenograft model. MDA-MB-231 cells expressing endogenous mutant p53 and stably expressing luciferase were injected into the left hip of CD1 nude/nude mice. When tumors reached visible size, bioluminescence (indicative of the number of cancer cells) was measured with the IVIS200 system. The mice were then treated by intra-tumoral injection, three times a week, with a mixture of 3 test peptides that exhibited mutant p53-reactivating ability (pCAPs 159, 155 and 174; 2 mg of each peptide). 35 days after initiation of treatment, the experiment was terminated. FIG. 19A shows a logarithmic scale graph demonstrating the luciferase readings in each tumor as a function of time after initiation of treatment (peptide injection). FIG. 19B shows live imaging images of mice 1-6 at the beginning of treatment. FIG. 19C shows live imaging images of treated mice 1-6 at day 35, when the experiment was terminated. Two of the tumors (mouse 1 and mouse 4) showed a partial response to the treatment, as measured by a decrease of 50% and 65%, respectively, in the luciferase signal after 35 days. Mice 2 and 5 showed a complete response, reaching bioluminescence readings that are as low as or close to the background threshold detection levels of the IVIS system (5×10⁶ photons) even after 21 days of treatment. Following cessation of the treatment after 35 days, mice numbers 2 and 5 were kept alive and monitored for an additional 21 days; no reappearance of tumors was detected either visually or by live imaging.

FIGS. 20A, 20B, 20C and 20D illustrate the in vivo effect of the indicated peptides in a mouse xenograft model. MDA-MB-231 cells expressing endogenous mutant p53 and stably expressing luciferase were injected into the left hip of CD1 nude/nude mice. When tumors reached visible size, bioluminescence (indicative of the number of cancer cells) was measured with the IVIS200 system. The mice were then treated by intra-tumoral injection, three times a week, with either a mixture of 3 control peptides that showed no phenotype in vitro (pCAPs 76, 77 and 12; 2 ug of each peptide) or a mixture of 3 test peptides that exhibited mutant p53-reactivating ability (pCAPs 159, 155 and 174; 2 ug of each peptide). FIGS. 20A and 20B show a logarithmic scale graph demonstrating the average luciferase readings in tumors as a function of time, before (until day 18) and after initiation of treatment (peptide injection). FIGS. 20C and 20D show live imaging images of mice, at the beginning of treatment (day 18, left) and 12 days into treatment (day 30, right). 40% of mice showed a complete response, reaching bioluminescence readings that are as low as or close to the background threshold detection levels of the IVIS system (5×10⁶ photons).

FIGS. 21A, 21B, 21C, 21D and 21E illustrate the in vivo effect of the indicated peptides in a mouse xenograft model. SW-480 colon cancer cells expressing endogenous mutant p53 and stably expressing luciferase were injected into the left hip of CD1 nude/nude mice. When tumors reached visible size, bioluminescence (indicative of the number of cancer cells) was measured with the IVIS200 system. The mice were then treated by intra-tumoral injection, three times a week, with either a mixture of 3 control peptides that showed no phenotype in vitro (pCAPs 76, 77 and 12; 2 ug of each peptide) or a mixture of 3 test peptides that exhibited mutant p53-reactivating ability (pCAPs 250, 308 and 325; 2 ug of each peptide). FIGS. 21A, 21B and 21C show a logarithmic scale graph demonstrating the average luciferase readings in tumors as a function of time, before (until day 0) and after initiation of treatment (peptide injection). FIGS. 21D and 21E shows box plot of tumors volume and tumor weight, respectively. As seen in FIGS. 21D and 21E tumors extracted from mice treated with either peptide mix or the pCAP-325 single peptide, are significantly smaller in size and weight compared to tumors extracted from mice treated with the control peptides (p-value <0.05).

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides highly potent peptides and modified peptide agents that can efficiently reactivate p53 conformational mutants, ideally by changing the mutant p53 proteins conformation and/or activity to resemble that of a wild type, functional p53 protein. The present invention thus provides peptides and their use in treating mutant p53 related conditions, where activation of present yet conformationally defective p53 proteins may be beneficial.

The present invention is based on the suprising identification of highly potent peptide and peptide-based agents that can efficiently reactivate p53 conformational mutants, more efficiently than previously known peptides identified for this use.

The present invention provides agents capable of at least partly elevating the anti-cancer and/or pro-apoptotic effect of mutant p53 proteins, and their use in treatment of any disease or condition caused by, or correlated with, a conformationally-aberrant p53 protein. Without being bound to any mechanism or theory, it is speculated that the conformational change in mutant p53 proteins upon binding to the agents provided by the present invention brings them closer to a 3D conformation of a wild type p53 protein, and thus at least partly restores at least part of the functions of a wild type p53 protein to the mutant p53 proteins.

More specifically, the present invention provides, in an aspect, a recombinant or synthetic peptide consisting of the amino-acid sequence set forth in any one of SEQ ID NOs:321-286.

The present invention further provides, in another aspect, a recombinant or synthetic peptide comprising the amino-acid sequence set forth in any one of SEQ ID NOs:321-286, wherein the peptide at least partially reactivates a mutant p53 protein.

The present invention further provides, in yet another aspect, a recombinant or synthetic peptide comprising a consensus motif of the amino-acid sequence set forth in any one of SEQ ID NOs:314, 268, 282, 328, 376, 298, 377, 378, 253, 20, 379, 302, 275, 380, 273, 381, 280 or 382, wherein the peptide at least partially reactivates a mutant p53 protein.

In certain embodiments, the peptide consists of the amino-acid sequence set forth in any one of SEQ ID NO:321, SEQ ID NO:314, SEQ ID NO:313, SEQ ID NO:310 or SEQ ID NO:307. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above consists the amino-acid sequence set forth in any one of SEQ ID NOs:321-302. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above consists the amino-acid sequence set forth in any one of SEQ ID NOs:321-312. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above consists the amino-acid sequence set forth in any one of SEQ ID NOs:321-316. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide comprises of the amino-acid sequence set forth in any one of SEQ ID NO:321, SEQ ID NO:314, SEQ ID NO:313, SEQ ID NO:310 or SEQ ID NO:307. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs:321-302. In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs:321-312. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide described above comprises the amino-acid sequence set forth in any one of SEQ ID NOs:321-316. Each possibility represents a separate embodiment of the invention.

The present invention further provides, in yet another aspect, a recombinant or synthetic peptide comprising the amino-acid sequence set forth in any one of SEQ ID NOs: 307, 310, 313, 314 and 321, wherein said peptide at least partially reactivates a mutant p53 protein.

The present invention further provides, in yet another aspect, a recombinant or synthetic peptide comprising the amino-acid sequence set forth in any one of SEQ ID NOs: 312, 314, 315, 316, 318 and 321, wherein said peptide at least partially reactivates a mutant p53 protein. Each possibility represents a separate embodiment of the invention.

According to a specific embodiment the consensus motif is as set forth in SEQ ID NO: 314.

In certain embodiments, the peptide consists of the amino-acid sequence set forth in any one of SEQ ID NOs: 307, 310, 313, 314 and 321, wherein said peptide at least partially reactivates a mutant p53 protein. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide consists of the amino-acid sequence set forth in any one of SEQ ID NOs: 312, 314, 315, 316, 318 and 321, wherein said peptide at least partially reactivates a mutant p53 protein. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide the peptide comprises SEQ ID NOs: 307, 310, 313, 314 and 321. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide comprises the amino-acid sequence set forth in SEQ ID NOs:321-316. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide is conjugated to at least one fatty acid moiety. In certain embodiments, the fatty acid is selected from the group consisting of myristic acid, lauric acid, palmitic acid and stearic acid. Each possibility represents a separate embodiment of the invention. In certain embodiments, the fatty acid is a myristoyl fatty acid.

In certain embodiments, the peptide at least partially changes the conformation of the mutant p53 protein to a conformation of a wild-type (WT) p53 protein.

Known in the art are antibodies that specifically recognize only wild type p53 proteins. Such antibodies are highly useful in determining whether a certain p53 protein, either wild type or mutant, holds the conformation of a wild type, functional p53 protein. Thus, in certain embodiments, the peptide at least partially changes the conformation of the mutant p53 protein such that the mutant p53 protein is recognized by a monoclonal antibody exclusively directed against a WT p53 protein or against a p53 protein holding a WT p53 protein conformation. In certain embodiments, the monoclonal antibody is Ab1620.

It should be understood that since p53 is expressed from both alleles, the overall content of intra-cellular p53 can be either wild-type (wt/wt), mixture of wt and mutant p53 (wt/mut) or mutant p53 only (when both alleles are mutated (mut/mut), or one allele is deleted (mut/−)). In cancer, the situation is often wt/mut, mut/mut or mut/−. Since p53 acts as a tetramer, mutant p53 proteins may abrogate the activity of wild type p53 proteins, which may exist in the cancer's cells. Therefore, the peptides provided by the present invention are particularly useful in treating cancers in which increasing the level of wild type p53 proteins is not fruitful.

In certain embodiments, the peptide at least partially restores the activity of the mutant p53 protein to at least one of the activities of a WT p53 protein.

As used herein the term “reducing” refers to statistically significantly decreasing a certain phenotype by at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%75%, 80%, 95% or even 100% as compared to a control (e.g., same cell/animal system treated with a control vehicle or non-treated at all) under the same assay conditions.

As used herein the term “increasing” or “improving” refers to statistically significantly increasing a certain phenotype by at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%75%, 80%, 95% or even 100% as compared to a control (e.g., same cell/animal system treated with a control vehicle or non-treated at all) under the same assay conditions.

In certain embodiments, the activity is reducing viability of cells expressing the mutant p53 protein. In certain embodiments, the activity is promoting apoptosis of cells expressing the mutant p53 protein. In certain embodiments, the activity is activating pro-apoptotic genes of cells expressing said mutant p53 protein. In certain embodiments, the pro-apoptotic genes are selected from the group consisting of CD95, Bax, DR4, DR5, PUMA, NOXA, Bid, 53AIP1 and PERP. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the activity is binding to a p53 consensus DNA binding element in cells expressing the mutant p53 protein. In certain embodiments, the consensus DNA binding element comprises or consists the amino-acid sequence set forth in SEQ ID NO:339.

Methods of monitoring cellular changes induced by the any of the peptides of the present invention are known in the art and include for example, the MTT test which is based on the selective ability of living cells to reduce the yellow salt MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) (Sigma, Aldrich St Louis, Mo., USA) to a purple-blue insoluble formazan precipitate; the BrDu assay [Cell Proliferation ELISA BrdU colorimetric kit (Roche, Mannheim, Germany]; the TUNEL assay [Roche, Mannheim, Germany]; the Annexin V assay [ApoAlert® Annexin V Apoptosis Kit (Clontech Laboratories, Inc., CA, USA)]; the Senescence associated-β-galactosidase assay (Dimri G P, Lee X, et al. 1995. A biomarker that identifies senescent human cells in culture and in aging skin in vivo. Proc Natl Acad Sci USA 92:9363-9367); as well as various RNA and protein detection methods (which detect level of expression and/or activity) which are further described hereinbelow.

In certain embodiments, the binding results in at least partial activation of an endogenous p53 target gene. In certain embodiments, the endogenous target gene is selected from the group consisting of p21, MDM2 and PUMA. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the mutant p53 protein is of a different conformation than a WT p53 protein. In certain embodiments, the mutant p53 protein is at least partly inactive compared to a WT p53 protein.

In certain embodiments, the mutant p53 protein is not recognized by a monoclonal antibody directed against a WT p53 protein. In certain embodiments, the mutant p53 protein, upon binding to the peptide, is recognized by a monoclonal antibody directed against a WT p53 protein. In certain embodiments, the monoclonal antibody is Ab1620.

In certain embodiments, the mutant p53 protein comprises a mutation selected from the group consisting of R175H, V143A, R249S, R273H, R280K, P309S, P151S, P151H, C176S, C176F, H179L, Q192R, R213Q, Y220C, Y220D, R245S, R282W, D281G, S241F, C242R, R248Q, R248W, D281G, R273C and V274F. Each possibility represents a separate embodiment of the invention.

In certain embodiments, the peptide comprises the consensus motif set forth in SEQ ID NO:314. In certain embodiments, the peptide comprises the amino-acid sequence set forth in any one of SEQ ID NO:321, SEQ ID NO:314, SEQ ID NO:313, SEQ ID NO:310 or SEQ ID NO:307. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide consists of the amino-acid sequence set forth in any one of SEQ ID NO:321, SEQ ID NO:314, SEQ ID NO:313, SEQ ID NO:310 or SEQ ID NO:307. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide comprises the amino-acid sequence set forth in any one of SEQ ID NOs:268, 282, 328, 376, 298, 377, 378, 253, 20, 379, 302, 275, 380, 273, 381, 280 or 382. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide comprises the amino-acid sequence set forth in any one of SEQ ID NOs:379, 302, 275, 380, 273, 381, 280 or 382. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide comprises the amino-acid sequence set forth in any one of SEQ ID NOs:302, 275, 380, 273, 381, 280 or 382. Each possibility represents a separate embodiment of the invention. According to a specific embodiment the consensus motif is as set forth in SEQ ID NO: 314. In certain embodiments, the peptide consists of the amino-acid sequence set forth in any one of SEQ ID NOs: 307, 310, 313, 314 and 321, wherein said peptide at least partially reactivates a mutant p53 protein. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide consists of the amino-acid sequence set forth in any one of SEQ ID NOs: 312, 314, 315, 316, 318 and 321, wherein said peptide at least partially reactivates a mutant p53 protein. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide the peptide comprises SEQ ID NOs: 307, 310, 313, 314 and 321. Each possibility represents a separate embodiment of the invention. In certain embodiments, the peptide comprises the amino-acid sequence set forth in SEQ ID NOs:321-316. Each possibility represents a separate embodiment of the invention.

The present invention further provides, in another aspect, an expression vector, capable of expressing the peptides described above.

The present invention further provides, in another aspect, a pharmaceutical composition, comprising the peptides described above.

The present invention further provides, in yet another aspect, a pharmaceutical composition, comprising the expression vector described above.

In an aspect, the pharmaceutical compositions described above are for use in treating a disease, disorder or condition associated with a mutant p53 protein.

In some embodiments, the disease is cancer. In some embodiments, the cancer is selected from the group consisting of breast cancer, colon cancer and lung cancer. Each possibility represents a separate embodiment of the invention. In some embodiments, the cancer cells express the mutant p53 protein.

The present invention further provides, in another aspect, a method of treating a disease, disorder or condition associated with a mutant p53 protein, comprising the step of administering a therapeutically effective amount of the pharmaceutical compositions described above to a subject in need thereof, thereby treating the disease, disorder or condition.

The present invention further provides, in yet another aspect, a kit comprising the pharmaceutical compositions described above.

In an aspect, the kit described above is for use in treating a disease, disorder or condition associated with a mutant p53 protein.

Definitions

To facilitate an understanding of the present invention, a number of terms and phrases are defined below. It is to be understood that these terms and phrases are for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance presented herein, in combination with the knowledge of one of ordinary skill in the art.

The term “recombinant or synthetic peptide” as used herein refers to a peptide produced by standard biotechnological methods known in the art, such as expression in bacteria or Solid-phase peptide synthesis (SPPS).

The term “capable of at least partially reactivating a mutant p53 protein” or “at least partially reactivates a mutant p53 protein” as interchangeably used herein refers to peptide, wherein upon binding of the peptide to a mutant p53 protein, the mutant p53 protein gains or increases an activity similar to a corresponding activity of a wild type p53 protein.

The term “consensus motif” as used herein refers to an amino acid sequence of at least three amino acids, which was found in more than one peptide provided by the present invention.

As used herein the phrase “permeability-enhancing moiety” refers to an agent which enhances translocation of any of the attached peptide across a cell membrane.

Any moiety known in the art to facilitate actively or passively or enhance permeability of compositions into cells may be used for conjugation with the peptide core according to the present invention. Non-limitative examples include: hydrophobic moieties such as fatty acids, steroids and bulky aromatic or aliphatic compounds; moieties which may have cell-membrane receptors or carriers, such as steroids, vitamins and sugars, natural and non-natural amino acids and proteinaceous moiety e.g., transporter peptides, also referred to as “cell penetrating peptides” or a CPP, poly-Arginine or poly-Lysine, a combination of same or an antibody. According to some embodiments, the proteinaceous moiety is a CPP.

According to some embodiments, the proteinaceous moiety is poly-Arginine.

According to some embodiments, the hydrophobic moiety is a lipid moiety or an amino acid moiety.

Cell-Penetrating Peptides (CPPs) are short peptides (≤40 amino acids), with the ability to gain access to the interior of almost any cell. They are highly cationic and usually rich in arginine and lysine amino acids. Indeed the present inventors have used positively charged amino acids (on either peptide termini) or poly-cationic amino acids (at least 2 e.g., 2-12) poly-Arg to impart the peptides with cell permeation. They have the exceptional property of carrying into the cells a wide variety of covalently and noncovalently conjugated cargoes such as proteins, oligonucleotides, and even 200 nm liposomes. Therefore, according to additional exemplary embodiment CPPs can be used to transport the peptides to the interior of cells.

TAT (transcription activator from HIV-1), pAntp (also named penetratin, Drosophila antennapedia homeodomain transcription factor) and VP22 (from Herpes Simplex virus) are examples of CPPs that can enter cells in a non-toxic and efficient manner and may be suitable for use with some embodiments of the invention. Protocols for producing CPPs-cargos conjugates and for infecting cells with such conjugates can be found, for example L Theodore et al. [The Journal of Neuroscience, (1995) 15(11): 7158-7167], Fawell S, et al. [Proc Natl Acad Sci USA, (1994) 91:664-668], and Jing Bian et al. [Circulation Research (2007) 100: 1626-1633].

However, the disclosure is not so limited, and any suitable penetrating agent may be used, as known by those of skill in the art.

When the peptides of the present invention are attached to cell penetrating peptides, it is contemplated that the full length peptide is no greater than 30 amino acids, no greater than 25 amino acids, no greater than 22 amino acids, no greater than 20 amino acids, no greater than 15 amino acids, no greater than 12 amino acids, no greater than 10 amino acids, no greater than 9 amino acids, no greater than 8 amino acids, or no greater than 7 amino acids.

The term “fatty acid moiety” as used herein refers to a part of a fatty acid that exhibits a particular set of chemical and pharmacologic characteristics similar to the corresponding complete fatty acid origin molecule. The term further refers to any molecular species and/or molecular fragment comprising the acyl component of a fatty (carboxylic) acid.

A permeability-enhancing moiety according to the present invention is preferably connected covalently to the peptide sequence via a direct bond or via a linker, to form a peptide conjugate. The permeability-enhancing moiety may be connected to any position in the peptide moiety, directly or through a spacer, preferably to the amino terminus of the peptide. According to certain embodiments, the permeability enhancing moiety is a fatty acid.

The term “Permeability” as used herein refers to the ability of an agent or substance to penetrate, pervade, or diffuse through a barrier, membrane, or a skin layer. A “cell permeability” or a “cell-penetration” moiety refers to any molecule known in the art which is able to facilitate or enhance penetration of molecules through membranes. Non-limitative examples include: hydrophobic moieties such as lipids, fatty acids, steroids and bulky aromatic or aliphatic compounds; moieties which may have cell-membrane receptors or carriers, such as steroids, vitamins and sugars, natural and non-natural amino acids, transporter peptides, nanoparticles and liposomes.

The hydrophobic moiety according to the invention may preferably comprise a lipid moiety or an amino acid moiety. According to a specific embodiment the hydrophobic moiety is selected from the group consisting of: phospholipids, steroids, sphingosines, ceramides, octyl-glycine, 2-cyclohexylalanine, benzolylphenylalanine, propionoyl (C₃); butanoyl (C₄); pentanoyl (C₅); caproyl (C₆); heptanoyl (C₇); capryloyl (C₈); nonanoyl (C₉); capryl (C₁₀); undecanoyl (C₁₁); lauroyl (C₁₂); tridecanoyl (C₁₃); myristoyl (C₁₄); pentadecanoyl (C₁₅); palmitoyl (C₁₆); phtanoyl ((CH₃)₄); heptadecanoyl (C₁₇); stearoyl (C₁₈); nonadecanoyl (C₁₉); arachidoyl (C₂₀); heniecosanoyl (C₂₁); behenoyl (C₂₂); trucisanoyl (C₂₃); and lignoceroyl (C₂₄); wherein said hydrophobic moiety is attached to said chimeric polypeptide with amide bonds, sulfhydryls, amines, alcohols, phenolic groups, or carbon-carbon bonds.

Other examples for lipidic moieties which may be used according to the present invention: Lipofectamine, Transfectace, Transfectam, Cytofectin, DMRIE, DLRIE, GAP-DLRIE, DOTAP, DOPE, DMEAP, DODMP, DOPC, DDAB, DOSPA, EDLPC, EDMPC, DPH, TMADPH, CTAB, lysyl-PE, DC-Cho, -alanyl cholesterol; DCGS, DPPES, DCPE, DMAP, DMPE, DOGS, DOHME, DPEPC, Pluronic, Tween, BRIJ, plasmalogen, phosphatidylethanolamine, phosphatidylcholine, glycerol-3-ethylphosphatidylcholine, dimethyl ammonium propane, trimethyl ammonium propane, diethylammonium propane, triethylammonium propane, dimethyldioctadecylammonium bromide, a sphingolipid, sphingomyelin, a lysolipid, a glycolipid, a sulfatide, a glycosphingolipid, cholesterol, cholesterol ester, cholesterol salt, oil, N-succinyldioleoylphosphatidylethanolamine, 1,2-dioleoyl-sn-glycerol, 1,3-dipalmitoyl-2-succinylglycerol, 1,2-dipalmitoyl-sn-3-succinylglycerol, 1-hexadecyl-2-palmitoylglycerophosphatidylethanolamine, palmitoylhomocystiene, N,N′-Bis (dodecyaminocarbonylmethylene)-N,N′-bis((—N,N,N-trimethylammoniumethyl-aminocarbonylmethylene)ethylenediamine tetraiodide; N,N″-Bis(hexadecylaminocarbonylmethylene)-N,N′,N″-tris((—N,N,N-trimethylammonium-ethylaminocarbonylmethylenediethylenetri amine hexaiodide; N,N′-Bis(dodecylaminocarbonylmethylene)-N,N″-bis((—N,N,N-trimethylammonium ethylaminocarbonylmethylene)cyclohexylene-1,4-diamine tetraiodide; 1,7,7-tetra-((—N,N,N,N-tetramethylammoniumethylamino-carbonylmethylene)-3-hexadecylaminocarbonyl-methylene-1,3,7-triaazaheptane heptaiodide; N,N,N′,N′-tetra((—N,N,N-trimethylammonium-ethylaminocarbonylmethylene)-N′-(1,2-dioleoylglycero-3-phosphoethanolamino carbonylmethylene)diethylenetriamine tetraiodide; dioleoylphosphatidylethanolamine, a fatty acid, a lysolipid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, a sphingolipid, a glycolipid, a glucolipid, a sulfatide, a glycosphingolipid, phosphatidic acid, palmitic acid, stearic acid, arachidonic acid, oleic acid, a lipid bearing a polymer, a lipid bearing a sulfonated saccharide, cholesterol, tocopherol hemisuccinate, a lipid with an ether-linked fatty acid, a lipid with an ester-linked fatty acid, a polymerized lipid, diacetyl phosphate, stearylamine, cardiolipin, a phospholipid with a fatty acid of 6-8 carbons in length, a phospholipid with asymmetric acyl chains, 6-(5-cholesten-3b-yloxy)-1-thio-b-D-galactopyranoside, digalactosyldiglyceride, 6-(5-cholesten-3b-yloxy)hexyl-6-amino-6-deoxy-1-thio-b-D-galactopyranoside, 6-(5-cholesten-3b-yloxy)hexyl-6-amino-6-deoxyl-1-thio-a-D-mannopyranoside, 12-(((7′-diethylamino-coumarin-3-yl)carbonyl)methylamino)-octadecanoic acid; N-[12-(((7′-diethylaminocoumarin-3-yl)carbonyl)methyl-amino) octadecanoyl]-2-aminopalmitic acid; cholesteryl)4′-trimethyl-ammonio)butanoate; N-succinyldioleoyl-phosphatidylethanolamine; 1,2-dioleoyl-sn-glycerol; 1,2-dipalmitoyl-sn-3-succinyl-glycerol; 1,3-dipalmitoyl-2-succinylglycerol, 1-hexadecyl-2-palmitoylglycero-phosphoethanolamine, and palmitoylhomocysteine.

According to a specific embodiment, the p53 protein is human p53. According to a specific embodiment, the subject, the biological sample derived therefrom or the cell (as described below) are of a human being.

The term “cells expressing the mutant p53 protein” as used herein refers to cells which express from at least one allele a mutant p53 protein. In certain embodiments, the term “cells expressing the mutant p53 protein” is interchangeable with “cancer cells”.

The term “pro-apoptotic genes” refers to a gene, or a multitude of genes, involved in apoptosis, either directly (such as certain caspases) or indirectly (for example, as part of a signal transduction cascade).

The term “pharmaceutical composition” as used herein refers to any composition comprising at least one pharmaceutically active ingredient.

The term “associated with a mutant p53 protein” as used herein refers to any disease, disorder or condition which is caused by a mutant p53 protein or related to the presence of a mutant p53 protein in a cell or an organ.

It should be understood that since p53 is expressed from both alleles, the overall content of intra-cellular p53 can be either wild-type (wt/wt), mixture of wt and mutant p53 (wt/mut) or mutant p53 only (when both alleles are mutated (mut/mut), or one allele is deleted (mut/−)). In cancer, the situation is often wt/mut, mut/mut or mut/−. Since p53 acts as a tetramer, mutant p53 proteins may abrogate the activity of wild type p53 proteins, which do exist in the cancer's cells. Therefore, the peptides provided by the present invention are particularly useful in treating cancers in which increasing the level of wild type p53 proteins is not fruitful.

The term “therapeutically effective amount” as used herein refers to an amount of a composition containing a peptide according to the present invention that is sufficient to reduce, decrease, and/or inhibit a disease, disorder or condition in an individual.

As used herein, the term p53 is directed to a p53 protein that can have a conformation of a WT p53, a mutated p53, or an intermediate conformation between WT and mutated p53.

As used herein, the terms “wild type p53”, “wt p53” and “WT p53” may interchangeably be used and are directed to a wild type p53 protein, having the conformation of a wild type p53 protein and hence, activity of a wild type p53 protein. In some embodiments, wild type p53 can be identified by a specific monoclonal antibody.

As used herein, the terms “mutant p53”, “Mut-p53”, “mutated p53”, and “p53 mutant” may interchangeably be used and are directed to a mutated p53 protein, incapable of efficiently functioning in a target cell. In some embodiments, a Mut-p53 cannot bind its target site. In some embodiments, a Mut-p53 is mutated at the DNA binding domain (DBD) region. In some embodiments, a Mut-p53 is misfolded in an inactive conformation. In some exemplary embodiments, the Mut-p53 is a temperature sensitive (ts) mut p53 R249S (R249S p53), a hot spot full length mutant p53 Mut-p53 R175H (R175H p53), or any other Mut-p53 protein. In some embodiments, a Mut-p53 is identified by a specific monoclonal antibody, capable of recognizing a misfolded conformation of p53 (induced by the mutation of the p53). In some embodiments, a Mut-p53 is identified by a specific monoclonal antibody.

The phrase “peptide reactivates a mutant p53 protein” as used herein refers to a peptide which upon its interaction with a mutant p53 protein, the mutant p53 protein increases at least one of his activities, wherein the activities are the activities of a wild type p53 protein. For example, upon its interaction with a peptide provided by the present invention, a mutant p53 protein may increase, directly or indirectly, the expression of pro-apoptotic proteins such as caspases in a cancer cell, in a similar way to what would a wild type p53 protein do in a similar situation.

As referred to herein, the terms “reactivating peptide”, “Mut-p53 reactivating peptide” or “the peptide” may interchangeably be used and are directed to a peptidic agent capable of at least partially restoring activity to Mut-p53. In some embodiments, the reactivating agent can reactivate a Mut-p53 by affecting the conformation of the Mut-p53, to assume a conformation which is more similar to or identical to a native, WT p53. In some embodiments, the reactivating agent can reactivate a Mut-p53 to restore binding of the Mut-p53 to a WT p53 binding site in a target DNA. In some embodiments, the reactivating agent can restore biochemical properties of the Mut-p53. In some embodiments, the reactivating agent can induce the Mut-p53 protein to exhibit p53-selective inhibition of cancer cells. In some embodiments, the reactivating agent can reactivate a Mut-p53 to have structural properties, biochemical properties, physiological properties and/or functional properties similar to or identical to a WT p53 protein. In some embodiments, the reactivating agent is a peptide. In some embodiments, the reactivating agent is a peptide having 3-30 amino acids in length. In some embodiments, the reactivating agent is a peptide having 7-30 amino acids in length. In some embodiments, the reactivating agent is a peptide having 12-30 amino acids in length. In some embodiments, the reactivating agent is a peptide having 3-25 amino acids in length. In some embodiments, the reactivating agent is a peptide having 7-25 amino acids in length. In some embodiments, the reactivating agent is a peptide having 12-25 amino acids in length. In some embodiments, the reactivating agent is a peptide having 3-22 amino acids in length. In some embodiments, the reactivating agent is a peptide having 7-22 amino acids in length. In some embodiments, the reactivating agent is a peptide having 12-22 amino acids in length. In some embodiments, the reactivating agent is a peptide having 7-9 amino acids in length. In some embodiments, the reactivating agent is a peptide having 6-9 amino acids in length. In some embodiments, the reactivating agent is a peptide having 7-10 amino acids in length. In some embodiments, the reactivating agent is a peptide having 6-10 amino acids in length. In some embodiments, the reactivating agent is a peptide having 5-20 amino acids in length. In some embodiments, the reactivating agent is a peptide having 6-15 amino acids in length. In some embodiments, the reactivating agent is a peptide having 7 or 12 amino acids in length.

The term “conformation” with respect to a protein is directed to the structural arrangement (folding) of a protein in space.

The terms “deep sequencing” and “next generation sequencing” may interchangeably be used and are directed to an enhanced sequencing method enabling the rapid parallel sequencing of multiple nucleic acid sequences.

The “phage display” method includes the screening of a library of phages, each expressing and presenting a specific, exogenous molecule, such as a peptide. The enrichment of phages that express and present a specific peptide is achieved by affinity selection of a phage library on immobilized target. In this “panning” process, binding phages (i.e. phages which express and present a peptide that can bind the immobilized target) are captured, whereas nonbinding phages (i.e., phages which do not express and present a peptide that can bind the immobilized target) are washed off. A next step in the method can include the elution and amplification of the bound phages by reinfection of E. coli cells with the identified phages. In some embodiments, a phage library can be an original library, or a commercially available phage display library.

The terms “polypeptide” and “peptide” are used interchangeably herein to refer to a polymer of amino acid residues. The terms apply to amino acid polymers in which one or more amino acid residue is an artificial chemical analogue of a corresponding naturally occurring amino acid, as well as to naturally occurring amino acid polymers.

The term “peptide” as used herein encompasses native peptides (either degradation products, synthetically synthesized peptides or recombinant peptides) and peptidomimetics (typically, synthetically synthesized peptides), as well as peptoids and semipeptoids which are peptide analogs, which may have, for example, modifications rendering the peptides more stable while in a body or more capable of penetrating into cells. Such modifications include, but are not limited to N terminus modification, C terminus modification, peptide bond modification, backbone modifications, and residue modification. Methods for preparing peptidomimetic compounds are well known in the art and are specified, for example, in Quantitative Drug Design, C. A. Ramsden Gd., Chapter 17.2, F. Choplin Pergamon Press (1992), which is incorporated by reference as if fully set forth herein. Further details in this respect are provided hereinunder.

Peptide bonds (—CO—NH—) within the peptide may be substituted, for example, by N-methylated amide bonds (—N(CH3)-CO—), ester bonds (—C(═O)—O—), ketomethylene bonds (—CO—CH2-), sulfinylmethylene bonds (—S(═O)—CH2-), α-aza bonds (—NH—N(R)—CO—), wherein R is any alkyl (e.g., methyl), amine bonds (—CH2-NH—), sulfide bonds (—CH2-S—), ethylene bonds (—CH2-CH2-), hydroxyethylene bonds (—CH(OH)—CH2-), thioamide bonds (—CS—NH—), olefinic double bonds (—CH═CH—), fluorinated olefinic double bonds (—CF═CH—), retro amide bonds (—NH—CO—), peptide derivatives (—N(R)—CH2-CO—), wherein R is the “normal” side chain, naturally present on the carbon atom.

These modifications can occur at any of the bonds along the peptide chain and even at several (2-3) bonds at the same time.

“Conservative substitution” refers to the substitution of an amino acid in one class by an amino acid of the same class, where a class is defined by common physico-chemical amino acid side chain properties and high substitution frequencies in homologous proteins found in nature, as determined, for example, by a standard Dayhoff frequency exchange matrix or BLOSUM matrix. Six general classes of amino acid side chains have been categorized and include: Class I (Cys); Class II (Ser, Thr, Pro, Ala, Gly); Class III (Asn, Asp, Gin, Glu); Class IV (His, Arg, Lys); Class V (He, Leu, Val, Met); and Class VI (Phe, Tyr, Trp). For example, substitution of an Asp for another Class III residue such as Asn, Gin, or Glu, is a conservative substitution.

Other classifications include positive amino acids (Arg, His, Lys), negative amino acids (Asp, Glu), polar uncharged (Ser, Thr, Asn, Gln), hydrophobic side chains (Ala, Val, Ile, Leu, Met, Phe, Tyr, Trp).

pCap 250 (SEQ ID NO: 321) comprising the core sequence of HSTPHP (SEQ ID NO: 314), may be conservatively modified to include any of the above amino acid conservative substitutions, wherein each option is considered as a separate embodiment.

“Non-conservative substitution” refers to the substitution of an amino acid in one class with an amino acid from another class; for example, substitution of an Ala, a Class II residue, with a Class III residue such as Asp, Asn, Glu, or Gin.

Natural aromatic amino acids, Trp, Tyr and Phe, may be substituted by non-natural aromatic amino acids such as 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic), naphthylalanine, ring-methylated derivatives of Phe, halogenated derivatives of Phe or O-methyl-Tyr. Other synthetic options are listed hereinbelow in Table B.

The peptides of some embodiments of the invention may also include one or more modified amino acids or one or more non-amino acid monomers (e.g. fatty acids, complex carbohydrates etc).

The term “amino acid” or “amino acids” is understood to include the 20 naturally occurring amino acids; those amino acids often modified post-translationally in vivo, including, for example, hydroxyproline, phosphoserine and phosphothreonine; and other unusual amino acids including, but not limited to, 2-aminoadipic acid, hydroxylysine, isodesmosine, nor-valine, nor-leucine and ornithine. Furthermore, the term “amino acid” includes both D- and L-amino acids.

Tables A and B below list naturally occurring amino acids (Table A), and non-conventional or modified amino acids (e.g., synthetic, Table B) which can be used with some embodiments of the invention.

TABLE A Three-Letter Amino Acid Abbreviation One-letter Symbol Alanine Ala A Arginine Arg R Asparagine Asn N Aspartic acid Asp D Cysteine Cys C Glutamine Gln Q Glutamic Acid Glu E Glycine Gly G Histidine His H Isoleucine Ile I Leucine Leu L Lysine Lys K Methionine Met M Phenylalanine Phe F Proline Pro P Serine Ser S Threonine Thr T Tryptophan Trp W Tyrosine Tyr Y Valine Val V Any amino acid as above Xaa X

TABLE B Non-conventional amino acid Code Non-conventional amino acid Code ornithine Orn hydroxyproline Hyp α-aminobutyric acid Abu aminonorbornyl- Norb carboxylate D-alanine Dala aminocyclopropane- Cpro carboxylate D-arginine Darg N-(3-guanidinopropyl)glycine Narg D-asparagine Dasn N-(carbamylmethyl)glycine Nasn D-aspartic acid Dasp N-(carboxymethyl)glycine Nasp D-cysteine Dcys N-(thiomethyl)glycine Ncys D-glutamine Dgln N-(2-carbamylethyl)glycine Ngln D-glutamic acid Dglu N-(2-carboxyethyl)glycine Nglu D-histidine Dhis N-(imidazolylethyl)glycine Nhis D-isoleucine Dile N-(1-methylpropyl)glycine Nile D-leucine Dleu N-(2-methylpropyl)glycine Nleu D-lysine Dlys N-(4-aminobutyl)glycine Nlys D-methionine Dmet N-(2-methylthioethyl)glycine Nmet D-ornithine Dorn N-(3-aminopropyl)glycine Norn D-phenylalanine Dphe N-benzylglycine Nphe D-proline Dpro N-(hydroxymethyl)glycine Nser D-serine Dser N-(1-hydroxyethyl)glycine Nthr D-threonine Dthr N-(3-indolylethyl) glycine Nhtrp D-tryptophan Dtrp N-(p-hydroxyphenyl)glycine Ntyr D-tyrosine Dtyr N-(1-methylethyl)glycine Nval D-valine Dval N-methylglycine Nmgly D-N-methylalanine Dnmala L-N-methylalanine Nmala D-N-methylarginine Dnmarg L-N-methylarginine Nmarg D-N-methylasparagine Dnmasn L-N-methylasparagine Nmasn D-N-methylasparatate Dnmasp L-N-methylaspartic acid Nmasp D-N-methylcysteine Dnmcys L-N-methylcysteine Nmcys D-N-methylglutamine Dnmgln L-N-methylglutamine Nmgln D-N-methylglutamate Dnmglu L-N-methylglutamic acid Nmglu D-N-methylhistidine Dnmhis L-N-methylhistidine Nmhis D-N-methylisoleucine Dnmile L-N-methylisolleucine Nmile D-N-methylleucine Dnmleu L-N-methylleucine Nmleu D-N-methyllysine Dnmlys L-N-methyllysine Nmlys D-N-methylmethionine Dnmmet L-N-methylmethionine Nmmet D-N-methylornithine Dnmorn L-N-methylornithine Nmorn D-N-methylphenylalanine Dnmphe L-N-methylphenylalanine Nmphe D-N-methylproline Dnmpro L-N-methylproline Nmpro D-N-methylserine Dnmser L-N-methylserine Nmser D-N-methylthreonine Dnmthr L-N-methylthreonine Nmthr D-N-methyltryptophan Dnmtrp L-N-methyltryptophan Nmtrp D-N-methyltyrosine Dnmtyr L-N-methyltyrosine Nmtyr D-N-methylvaline Dnmval L-N-methylvaline Nmval L-norleucine Nle L-N-methylnorleucine Nmnle L-norvaline Nva L-N-methylnorvaline Nmnva L-ethylglycine Etg L-N-methyl-ethylglycine Nmetg L-t-butylglycine Tbug L-N-methyl-t-butylglycine Nmtbug L-homophenylalanine Hphe L-N-methyl-homophenylalanine Nmhphe α-naphthylalanine Anap N-methyl-α-naphthylalanine Nmanap penicillamine Pen N-methylpenicillamine Nmpen γ-aminobutyric acid Gabu N-methyl-γ-aminobutyrate Nmgabu cyclohexylalanine Chexa N-methyl-cyclohexylalanine Nmchexa cyclopentylalanine Cpen N-methyl-cyclopentylalanine Nmcpen α-amino-α-methylbutyrate Aabu N-methyl-α-amino-α- Nmaabu methylbutyrate α-aminoisobutyric acid Aib N-methyl-α-aminoisobutyrate Nmaib D-α-methylarginine Dmarg L-α-methylarginine Marg D-α-methylasparagine Dmasn L-α-methylasparagine Masn D-α-methylaspartate Dmasp L-α-methylaspartate Masp D-α-methylcysteine Dmcys L-α-methylcysteine Mcys D-α-methylglutamine Dmgln L-α-methylglutamine Mgln D-α-methyl glutamic acid Dmglu L-α-methylglutamate Mglu D-α-methylhistidine Dmhis L-α-methylhistidine Mhis D-α-methylisoleucine Dmile L-α-methylisoleucine Mile D-α-methylleucine Dmleu L-α-methylleucine Mleu D-α-methyllysine Dmlys L-α-methyllysine Mlys D-α-methylmethionine Dmmet L-α-methylmethionine Mmet D-α-methylornithine Dmorn L-α-methylornithine Morn D-α-methylphenylalanine Dmphe L-α-methylphenylalanine Mphe D-α-methylproline Dmpro L-α-methylproline Mpro D-α-methylserine Dmser L-α-methylserine Mser D-α-methylthreonine Dmthr L-α-methylthreonine Mthr D-α-methyltryptophan Dmtrp L-α-methyltryptophan Mtrp D-α-methyltyrosine Dmtyr L-α-methyltyrosine Mtyr D-α-methylvaline Dmval L-α-methylvaline Mval N-cyclobutylglycine Ncbut L-α-methylnorvaline Mnva N-cycloheptylglycine Nchep L-α-methylethylglycine Metg N-cyclohexylglycine Nchex L-α-methyl-t-butylglycine Mtbug N-cyclodecylglycine Ncdec L-α-methyl-homophenylalanine Mhphe N-cyclododecylglycine Ncdod α-methyl-α-naphthylalanine Manap N-cyclooctylglycine Ncoct α-methylpenicillamine Mpen N-cyclopropylglycine Ncpro α-methyl-γ-aminobutyrate Mgabu N-cycloundecylglycine Ncund α-methyl-cyclohexylalanine Mchexa N-(2-aminoethyl)glycine Naeg α-methyl-cyclopentylalanine Mcpen N-(2,2-diphenylethyl)glycine Nbhm N-(N-(2,2-diphenylethyl)carbamylmethyl- Nnbhm glycine N-(3,3-diphenylpropyl)glycine Nbhe N-(N-(3,3-diphenylpropyl)carbamylmethyl- Nnbhe glycine 1-carboxy-1-(2,2-diphenyl Nmbc 1,2,3,4-tetrahydroisoquinoline-3- Tic ethylamino)cyclopropane carboxylic acid phosphoserine pSer phosphothreonine pThr phosphotyrosine pTyr O-methyl-tyrosine 2-aminoadipic acid hydroxylysine

The peptides of some embodiments of the invention are preferably utilized in a linear form, although it will be appreciated that in cases where cyclicization does not severely interfere with peptide characteristics, cyclic forms of the peptide can also be utilized.

In order to improve bioavailability, the peptide may comprise at least one D amino acid.

Alternatively or additionally, the peptide may comprise C-terminal amidation.

Yet alternatively or additionally the peptide may be conjugated to non-proteinaceous non-toxic moiety such as, but are not limited to, polyethylene glycol (PEG), Polyvinyl pyrrolidone (PVP), poly(styrene comaleic anhydride) (SMA), and divinyl ether and maleic anhydride copolymer (DIVEMA).

It will be appreciated that the peptides of the invention can also utilize peptide homologues which exhibit the desired activity (e.g., reactivation of p53 mutants)), also referred to herein as functional equivalents, whereby the activity of the peptide homologue is determined according to methods known in the art such as described herein. Such homologues can be, for example, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identical to SEQ ID NO: 286-321 (e.g., 302-321, 312-321, 316-321 e.g., 321 or 314, e.g., 321), as determined using the BestFit software.

The terms “nucleic acid”, “polynucleotide”, “oligonucleotide” or “oligo” relates to a single-stranded or double-stranded polymer composed of DNA (Deoxyribonucleic acid) nucleotides, RNA (Ribonucleic acid) nucleotides or a combination of both types, and may include natural nucleotides, chemically modified nucleotides and synthetic nucleotides.

“Chemically modified” refers to an amino acid that is modified either by natural processes, or by chemical modification techniques which are well known in the art. Among the numerous known modifications, typical, but not exclusive examples include: acetylation, acylation, amidation, ADP-ribosylation, glycosylation, glycosaminoglycanation, GPI anchor formation, covalent attachment of a lipid or lipid derivative, methylation, myristlyation, pegylation, prenylation, phos-phorylation, ubiqutination, or any similar process.

As referred to herein, the term “treating a disease” or “treating a condition” is directed to administering a composition, which includes at least one agent, effective to ameliorate symptoms associated with a disease, to lessen the severity or cure the disease, or to prevent the disease from occurring in a subject. Administration may include any administration route. In some embodiments, the disease is a disease that is caused by or related to the presence of a mutated p53 in a cell, tissue, organ, body, and the like. In some embodiments, the disease is cancer. In some embodiments, the cancer is selected from the group consisting of breast cancer, colon cancer and lung cancer. Each possibility represents a separate embodiment of the invention. In some embodiments, the subject is a mammal, such as a human. In some embodiments, the subject is a mammal animal. In some embodiments, the subject is a non-mammal animal.

The term “expression”, as used herein, refers to the production of a desired end-product molecule in a target cell. The end-product molecule may include, for example an RNA molecule; a peptide or a protein; and the like; or combinations thereof.

The term “construct”, as used herein refers to an artificially assembled or isolated nucleic acid molecule which may be one or more nucleic acid sequences, wherein the nucleic acid sequences may comprise coding sequences (that is, sequence which encodes an end product), regulatory sequences, non-coding sequences, or any combination thereof. The term construct encompasses, for example, vector but should not be seen as being limited thereto.

“Expression vector” refers to vectors that have the ability to incorporate and express heterologous nucleic acid fragments (such as, for example, DNA), in a foreign cell. In other words, an expression vector comprises nucleic acid sequences/fragments (such as DNA, mRNA, tRNA, rRNA), capable of being transcribed. Many prokaryotic and eukaryotic expression vectors are known and/or commercially available. Selection of appropriate expression vectors is within the knowledge of those having skill in the art.

The terms “Upstream” and “Downstream”, as used herein refers to a relative position in a nucleotide sequence, such as, for example, a DNA sequence or an RNA sequence. As well known, a nucleotide sequence has a 5′ end and a 3′ end, so called for the carbons on the sugar (deoxyribose or ribose) ring of the nucleotide backbone. Hence, relative to the position on the nucleotide sequence, the term downstream relates to the region towards the 3′ end of the sequence. The term upstream relates to the region towards the 5′ end of the strand.

As used herein, the terms “introducing”, “transfection” or “transfecting” and “infection” or “infecting” may interchangeably be used and refer to the transfer of molecules, such as, for example, nucleic acids, polynucleotide molecules, vectors, and the like into a target cell(s), and more specifically into the interior of a membrane-enclosed space of a target cell(s). The molecules can be “introduced” into the target cell(s) by any means known to those of skill in the art, for example as taught by Sambrook et al. Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, New York (2001), the contents of which are incorporated by reference herein. Means of “introducing” molecules into a cell include, for example, but are not limited to: heat shock, calcium phosphate transfection, PEI transfection, electroporation, lipofection, transfection agent(s), viral-mediated transfer, and the like, or combinations thereof. The transfection of the cell may be performed on any type of cell, of any origin.

As referred to herein, the term “exogenous gene” is directed to a gene (or any part thereof) which is introduced from the exterior into a cell. In some embodiments, the exogenous gene is inserted in the form of a polynucleotide (for example, DNA, RNA, and the like). In some embodiments, the exogenous gene is capable of being expressed in the cell.

In some embodiments, the exogenous gene is overexpressed within the cell.

As used herein the term “about” in reference to a numerical value stated herein is to be understood as the stated value +/−10%.

In some embodiments, the reactivating peptide can reactivate a Mut-p53 to have structural properties, biochemical properties, physiological properties and/or functional properties similar to or identical to a WT p53 protein.

According to some embodiments, there are provided Mut-p53 reactivating peptides, wherein the peptides are in the length of about 3-25 amino acids. In some embodiments, the Mut-p53 reactivating peptides are in the length of about 4-15 amino acids. In some embodiments, the Mut-p53 reactivating peptides are in the length of about 7-12 amino acids.

In some embodiments, the Mut-p53 reactivating peptides are in the length of 7 amino acids. In some embodiments, the Mut-p53 reactivating peptides are in the length of 12 amino acids. Each possibility represents a separate embodiment of the invention.

Other peptide lengths are recited throughout the application. Each possibility represents a separate embodiment of the invention.

In some embodiments, there is provided a Mut-p53 reactivating peptide having an amino acid sequence as denoted by any one of the peptide sequences in Tables 6, 7 or 8, herein below.

According to some embodiments, a Mut-p53 reactivating peptide can affect Mut-p53 such that it can trans-activates a reporter gene (such as Luciferase) having WT p53 binding element in its promoter. In some embodiments the transactivation of the reporter gene may be performed in vitro (for example, in a test tube or well), or in-vivo in a cell, harboring the reporter gene construct.

According to some embodiments, a Mut-p53 reactivating peptide can bind to the DNA binding Domain (DBD) of a mutated p53. In some embodiments, the mutated p53 harbors a mutation in its DNA binding domain (DBD).

In some embodiments, cancer is adrenocortical carcinoma, anal cancer, bladder cancer, brain tumor, brain stem glioma, brain tumor, cerebellar astrocytoma, cerebral astrocytoma, ependymoma, medulloblastoma, supratentorial primitive neuroectodermal, pineal tumors, hypothalamic glioma, breast cancer, carcinoid tumor, carcinoma, cervical cancer, colon cancer, endometrial cancer, esophageal cancer, extrahepatic bile duct cancer, ewings family of tumors (pnet), extracranial germ cell tumor, eye cancer, intraocular melanoma, gallbladder cancer, gastric cancer, germ cell tumor, extragonadal, gestational trophoblastic tumor, head and neck cancer, hypopharyngeal cancer, islet cell carcinoma, laryngeal cancer, leukemia, acute lymphoblastic, leukemia, oral cavity cancer, liver cancer, lung cancer, small cell, lymphoma, AIDS-related, lymphoma, central nervous system (primary), lymphoma, cutaneous T-cell, lymphoma, hodgkin's disease, non-hodgkin's disease, malignant mesothelioma, melanoma, merkel cell carcinoma, metasatic squamous carcinoma, multiple myeloma, plasma cell neoplasms, mycosis fungoides, myelodysplastic syndrome, myeloproliferative disorders, nasopharyngeal cancer, neuroblastoma, oropharyngeal cancer, osteosarcoma, ovarian epithelial cancer, ovarian germ cell tumor, ovarian low malignant potential tumor, pancreatic cancer, exocrine, pancreatic cancer, islet cell carcinoma, paranasal sinus and nasal cavity cancer, parathyroid cancer, penile cancer, pheochromocytoma cancer, pituitary cancer, plasma cell neoplasm, prostate cancer, rhabdomyosarcoma, rectal cancer, renal cell cancer, salivary gland cancer, sezary syndrome, skin cancer, cutaneous T-cell lymphoma, skin cancer, kaposi's sarcoma, skin cancer, melanoma, small intestine cancer, soft tissue sarcoma, soft tissue sarcoma, testicular cancer, thymoma, malignant, thyroid cancer, urethral cancer, uterine cancer, sarcoma, unusual cancer of childhood, vaginal cancer, vulvar cancer, or wilms' tumor.

In some embodiments, the cancer is a lung cancer.

In some embodiments, the cancer is an ovarian cancer.

In some embodiments, the cancer is a triple negative breast cancer.

In some embodiments, cancer is a non-solid tumor such as a blood cancer. In another embodiment, a non-solid tumor or blood cancer is leukemia or lymphoma. In another embodiment, a non-solid tumor or blood cancer is acute lymphoblastic leukemia (ALL). In another embodiment, a non-solid tumor or blood cancer is acute myelogenous leukemia (AML). In another embodiment, a non-solid tumor or blood cancer is chronic lymphocytic leukemia (CLL). In another embodiment, a non-solid tumor or blood cancer is small lymphocytic lymphoma (SLL). In another embodiment, a non-solid tumor or blood cancer is chronic myelogenous leukemia (CML). In another embodiment, a non-solid tumor or blood cancer is acute monocytic leukemia (AMOL). In another embodiment, a non-solid tumor or blood cancer is Hodgkin's lymphomas (any of the four subtypes). In another embodiment, a non-solid tumor or blood cancer is Non-Hodgkin's lymphomas (any of the subtypes). In another embodiment, a non-solid tumor or blood cancer is myeloid leukemia.

For use in the methods of the invention, the reactivating peptides may be formulated in a conventional manner using one or more pharmaceutically acceptable carriers, stabilizers or excipients (vehicles) to form a pharmaceutical composition as is known in the art, in particular with respect to protein active agents. Carrier(s) are “acceptable” in the sense of being compatible with the other ingredients of the composition and not deleterious to the recipient thereof. Suitable carriers typically include physiological saline or ethanol polyols such as glycerol or propylene glycol.

The reactivating peptides may be formulated as neutral or salt forms. Pharmaceutically acceptable salts include the acid addition salts (formed with free amino groups) and which are formed with inorganic acids such as hydrochloric or phosphoric acids, or such organic acids such as acetic, oxalic, tartaric and maleic. Salts formed with the free carboxyl groups may also be derived from inorganic bases such as sodium, potassium, ammonium, calcium, or ferric hydroxides, and organic bases as isopropylamine, trimethylamine, 2-ethylamino ethanol, histidine and procaine.

The compositions may be suitably formulated for intravenous, intramuscular, subcutaneous, or intraperitoneal administration and conveniently comprise sterile aqueous solutions of the reactivating peptides, which are preferably isotonic with the blood of the recipient. Such formulations are typically prepared by dissolving solid active ingredient in water containing physiologically compatible substances such as sodium chloride, glycine, and the like, and having a buffered pH compatible with physiological conditions to produce an aqueous solution, and rendering said solution sterile. These may be prepared in unit or multi-dose containers, for example, sealed ampoules or vials.

The compositions may incorporate a stabilizer, such as for example polyethylene glycol, proteins, saccharides (for example trehalose), amino acids, inorganic acids and admixtures thereof. Stabilizers are used in aqueous solutions at the appropriate concentration and pH. The pH of the aqueous solution is adjusted to be within the range of 5.0-9.0, preferably within the range of 6-8. In formulating the reactivating peptides, anti-adsorption agent may be used. Other suitable excipients may typically include an antioxidant such as ascorbic acid.

The compositions may be formulated as controlled release preparations which may be achieved through the use of polymer to complex or absorb the proteins. Appropriate polymers for controlled release formulations include for example polyester, polyamino acids, polyvinyl, pyrrolidone, ethylenevinylacetate, and methylcellulose. Another possible method for controlled release is to incorporate the reactivating peptides into particles of a polymeric material such as polyesters, polyamino acids, hydrogels, poly(lactic acid) or ethylene vinylacetate copolymers. Alternatively, instead of incorporating these agents into polymeric particles, it is possible to entrap these materials in microcapsules prepared, for example, by coacervation techniques or by interfacial polymerization, for example, hydroxymethylcellulose or gelatin-microcapsules and poly(methylmethacylate) microcapsules, respectively, or in colloidal drug delivery systems, for example, liposomes, albumin microspheres, microemulsions, nanoparticles, and nanocapsules or in macroemulsions.

In some embodiments, the reactivating peptides of the invention may be formulated in peroral or oral compositions and in some embodiments, comprise liquid solutions, emulsions, suspensions, and the like. In some embodiments, pharmaceutically-acceptable carriers suitable for preparation of such compositions are well known in the art. In some embodiments, liquid oral compositions comprise from about 0.001% to about 0.9% of reactivating peptides, or in another embodiment, from about 0.01% to about 10%.

In some embodiments, compositions for use in the methods of this invention comprise solutions or emulsions, which in some embodiments are aqueous solutions or emulsions comprising a safe and effective amount of a reactivating peptide and optionally, other compounds, intended for topical intranasal administration.

In some embodiments, injectable solutions of the invention are formulated in aqueous solutions. In one embodiment, injectable solutions of the invention are formulated in physiologically compatible buffers such as Hank's solution, Ringer's solution, or physiological salt buffer. In some embodiments, for transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art.

In one embodiment, the preparations described herein are formulated for parenteral administration, e.g., by bolus injection or continuous infusion. In some embodiments, formulations for injection are presented in unit dosage form, e.g., in ampoules or in multidose containers with optionally, an added preservative. In some embodiments, compositions are suspensions, solutions or emulsions in oily or aqueous vehicles, and contain formulatory agents such as suspending, stabilizing and/or dispersing agents.

The reactivating peptides of the invention may be administered by any suitable administration route, selected from oral, topical, transdermal or parenteral administration.

According to some embodiments the route of administration is via topical application selected from dermal, vaginal, rectal, inhalation, intranasal, ocular, auricular and buccal.

According to some embodiments the route of administration is via parenteral injection. In various embodiments, the step of administering is carried out by a parenteral route selected from the group consisting of intravenous, intramuscular, subcutaneous, intradermal, intraperitoneal, intraarterial, intracerebral, intracerebroventricular, intraosseus and intrathecal. For example, the reactivating peptides may be administered systemically, for example, by parenteral routes, such as, intraperitoneal (i.p.), intravenous (i.v.), subcutaneous, or intramuscular routes. The reactivating peptides of the invention and/or any optional additional agent may be administered systemically, for example, by intranasal administration. The reactivating peptides of the invention and/or any optional additional agent may be administered systemically, for example, by oral administration, by using specific compositions or formulations capable of providing oral bioavailability to proteins. The reactivating peptides of the invention and/or any optional additional agent may be administered locally.

The reactivating peptides may be administered in the range of about 0.1 to about 20 mg/kg of subject weight, commonly about 0.5 to about 10 mg/kg, and often about 1 to about 5 mg/kg. In some cases it may be advantageous to administer a large loading dose followed by periodic (e.g., weekly) maintenance doses over the treatment period. The reactivating peptides can also be delivered by slow-release delivery systems, pumps, and other known delivery systems for continuous infusion. Dosing regimens may be varied to provide the desired circulating levels of particular reactivating peptides based on its pharmacokinetics. Thus, doses are calculated so that the desired circulating level of therapeutic agent is maintained.

Typically, the effective dose is determined by the activity of the reactivating peptides and the condition of the subject, as well as the body weight or surface area of the subject to be treated. The size of the dose and the dosing regime is also determined by the existence, nature, and extent of any adverse side effects that accompany the administration of the reactivating peptides in the particular subject.

In some embodiments, there is provided a kit for treating or preventing a p53 related condition. In some embodiments, the kit comprises a container (such as a vial) comprising a Mut-p53 reactivating peptide in a suitable buffer and instructions for use for administration of the reactivating peptide.

It is suggested that the efficacy of treatment with the peptides of the invention may be augmented when combined with gold standard treatments (e.g., anti-cancer therapy). Thus, the peptide can be used to treat diseases or conditions associated with p53 (as described hereinabove) alone or in combination with other established or experimental therapeutic regimen for such disorders. It will be appreciated that treatment with additional therapeutic methods or compositions has the potential to significantly reduce the effective clinical doses of such treatments, thereby reducing the often devastating negative side effects and high cost of the treatment.

Therapeutic regimen for treatment of cancer suitable for combination with the peptides of some embodiments of the invention or polynucleotide encoding same include, but are not limited to chemotherapy, radiotherapy, phototherapy and photodynamic therapy, surgery, nutritional therapy, ablative therapy, combined radiotherapy and chemotherapy, brachiotherapy, proton beam therapy, immunotherapy, cellular therapy and photon beam radiosurgical therapy. According to a specific embodiment, the chometherapy is platinum-based.

Anti-Cancer Drugs

Anti-cancer drugs that can be co-administered with the compounds of the invention include, but are not limited to Acivicin; Aclarubicin; Acodazole Hydrochloride; Acronine; Adriamycin; Adozelesin; Aldesleukin; Altretamine; Ambomycin; Ametantrone Acetate; Aminoglutethimide; Amsacrine; Anastrozole; Anthramycin; Asparaginase; Asperlin; Azacitidine; Azetepa; Azotomycin; Batimastat; Benzodepa; Bicalutamide; Bisantrene Hydrochloride; Bisnafide Dimesylate; Bizelesin; Bleomycin Sulfate; Brequinar Sodium; Bropirimine; Busulfan; Cactinomycin; Calusterone; Caracemide; Carbetimer; Carboplatin; Carmustine; Carubicin Hydrochloride; Carzelesin; Cedefingol; Chlorambucil; Cirolemycin; Cisplatin; Cladribine; Crisnatol Mesylate; Cyclophosphamide; Cytarabine; Dacarbazine; Dactinomycin; Daunorubicin Hydrochloride; Decitabine; Dexormaplatin; Dezaguanine; Dezaguanine Mesylate; Diaziquone; Docetaxel; Doxorubicin; Doxorubicin Hydrochloride; Droloxifene; Droloxifene Citrate; Dromostanolone Propionate; Duazomycin; Edatrexate; Eflornithine Hydrochloride; Elsamitrucin; Enloplatin; Enpromate; Epipropidine; Epirubicin Hydrochloride; Erbulozole; Esorubicin Hydrochloride; Estramustine; Estramustine Phosphate Sodium; Etanidazole; Etoposide; Etoposide Phosphate; Etoprine; Fadrozole Hydrochloride; Fazarabine; Fenretinide; Floxuridine; Fludarabine Phosphate; Fluorouracil; Flurocitabine; Fosquidone; Fostriecin Sodium; Gemcitabine; Gemcitabine Hydrochloride; Hydroxyurea; Idarubicin Hydrochloride; Ifosfamide; Ilmofosine; Interferon Alfa-2a; Interferon Alfa-2b; Interferon Alfa-n1; Interferon Alfa-n3; Interferon Beta-Ia; Interferon Gamma-Ib; Iproplatin; Irinotecan Hydrochloride; Lanreotide Acetate; Letrozole; Leuprolide Acetate; Liarozole Hydrochloride; Lometrexol Sodium; Lomustine; Losoxantrone Hydrochloride; Masoprocol; Maytansine; Mechlorethamine Hydrochloride; Megestrol Acetate; Melengestrol Acetate; Melphalan; Menogaril; Mercaptopurine; Methotrexate; Methotrexate Sodium; Metoprine; Meturedepa; Mitindomide; Mitocarcin; Mitocromin; Mitogillin; Mitomalcin; Mitomycin; Mitosper; Mitotane; Mitoxantrone Hydrochloride; Mycophenolic Acid; Nocodazole; Nogalamycin; Ormaplatin; Oxisuran; Paclitaxel; Pegaspargase; Peliomycin; Pentamustine; Peplomycin Sulfate; Perfosfamide; Pipobroman; Piposulfan; Piroxantrone Hydrochloride; Plicamycin; Plomestane; Porfimer Sodium; Porfiromycin; Prednimustine; Procarbazine Hydrochloride; Puromycin; Puromycin Hydrochloride; Pyrazofurin; Riboprine; Rogletimide; Safingol; Safingol Hydrochloride; Semustine; Simtrazene; Sparfosate Sodium; Sparsomycin; Spiro germanium Hydrochloride; Spiromustine; Spiroplatin; Streptonigrin; Streptozocin; Sulofenur; Talisomycin; Taxol; Tecogalan Sodium; Tegafur; Teloxantrone Hydrochloride; Temoporfin; Teniposide; Teroxirone; Testolactone; Thiamiprine; Thioguanine; Thiotepa; Tiazofuirin; Tirapazamine; Topotecan Hydrochloride; Toremifene Citrate; Trestolone Acetate; Triciribine Phosphate; Trimetrexate; Trimetrexate Glucuronate; Triptorelin; Tubulozole Hydrochloride; Uracil Mustard; Uredepa; Vapreotide; Verteporfin; Vinblastine Sulfate; Vincristine Sulfate; Vindesine; Vindesine Sulfate; Vinepidine Sulfate; Vinglycinate Sulfate; Vinleurosine Sulfate; Vinorelbine Tartrate; Vinrosidine Sulfate; Vinzolidine Sulfate; Vorozole; Zeniplatin; Zinostatin; Zorubicin Hydrochloride. Additional antineoplastic agents include those disclosed in Chapter 52, Antineoplastic Agents (Paul Calabresi and Bruce A. Chabner), and the introduction thereto, 1202-1263, of Goodman and Gilman's “The Pharmacological Basis of Therapeutics”, Eighth Edition, 1990, McGraw-Hill, Inc. (Health Professions Division).

The following examples are presented in order to more fully illustrate certain embodiments of the invention. They should in no way, however, be construed as limiting the broad scope of the invention. One skilled in the art can readily devise many variations and modifications of the principles disclosed herein without departing from the scope of the invention.

EXAMPLES

Materials and Methods

Purification of Recombinant Full Length (FL) Proteins from Sf9 Cells: Mutant p53 R249S, Mutant p53 R175H and WT p53:

2×10⁷ sf9 cells in the log-phase were grown in nine 175 cm² flasks containing 25 ml of media and incubated overnight at 27° C. Baculoviruses containing a recombinant p53 were added into each flask, and incubated for 72 hrs. Cells were scraped from the flasks, and centrifuged at 4° C. (3200 g for 5 min), the media was removed and the cell pellet was washed twice with ice-cold isotonic buffer (10 mM Na₂HPO₄, pH 7.2, 130 mM NaCl, 1 mM DTPA—diethylenetriaminepentaacetic acid). To lyse cells, the cells were resuspended in 50 ml of Buffer A (20 mM Tris-HCl, pH 8.0, 12% sucrose, 2 mM EGTA, 2 mM PMSF, 5 mM DTT) with 0.2% Triton X-100 by gentle inversion. Nuclei centrifuged at 5600G for 8 min and the supernatant was removed. Nuclei was lysed by adding 20 ml of Buffer B (20 mM Tris-HCl, pH 8.0, 12% sucrose, 2 mM EGTA, 2 mM PMSF, 10 mM DTT+protease inhibitors) with 0.5M NaCl and were vortexed vigorously and incubated for 20 min on ice. The nuclear lysate was transferred to ultracentrifuge tubes and centrifuged at 100,000 g for 60 min at 4° C. The supernatant was removed and diluted with Buffer B to a final concentration 0.04 M of NaCl, then centrifuged at 20,000 g for 5 min at 4° C. The nuclear lysate was loaded onto a 5 ml Hitrap Q FF (fast flow) (Amersham Pharmacia) ion-exchange column, pre-washed with 50 ml of buffer A. Then, the column was washed with buffers containing higher salt concentrations to elute the protein. For example, in the case of the mutant p53 R249S, the protein eluted from the Ion exchange column at ˜150 mM NaCl. The protein was further purified by gel-filtration chromatography using a preparative Superdex 75 column (Amersham Pharmacia Biotech), pre-equilibrated with 20 mM sodium citrate pH 6.1, 150 mM NaCl, 10 μM ZnCl₂, and 10 mM DTT. Fractions containing purified protein were pooled together and concentrated to 6-7 mg/ml, aliquoted and stored at −80° C. The fractions obtained after each purification step were analyzed on dot-blot for presence of mutant p53 and subsequently on SDS-PAGE with Coomassie blue staining to check purity of the fractions.

Sandwich ELISA

96-well plates were coated using 3 different antibodies (1 type of antibody (Ab) in each well): PAb421 recognizes both conformations of p53 and binds to a C-terminus epitope; PAb240 recognizes mutant conformation of p53, binds to epitope within the core domain (amino acids 212-217) (Stephen, C. W. and D. P. Lane, Mutant conformation of p53. Precise epitope mapping using a filamentous phage epitope library. J. Mol. Biol., 1992. 225(3): p. 577-83) which is accessible to the Ab when the protein is partially denatured (for example, when the DBD is mutated); and PAb1620, which recognizes WT conformation of p53, binds to epitope with in the core domain (aa 156, 206-210), formed when folding is in WT conformation (Wang, P. L., F. Salt, and G. Winter, The ‘wild type’ conformation of p53: epitope mapping using hybrid proteins. Oncogene, 2001. 20(18): p. 2318-24).

Wells were incubated overnight (ON) with 100 μl Ab (5 μg/ml) in room temp (RT). The liquid was discarded, and the wells were washed 3 times with Phosphate buffered saline (PBS), 200 μl per each wash. Next, blocking with 200 μl of 5% bovine serum albumin (BSA) diluted in PBS in each well for 1.5 hours at room temperature (RT) was performed. Blocking buffer was discarded, followed by 3 washes in PBS as described above. Samples of mutant and WT p53 proteins (100 μl, 10 μg/ml), together with control peptides pCAP-710 (LPNPPER, SEQ ID NO:328) and pCAP-1220 (FRSFAIPLVVPF, SEQ ID NO:368) (5 μg/ml, Sigma Aldrich, or with test peptides 1-153 (5 μg/ml), were incubated for 1.5 hours together, and then added to the wells. Samples were rotated and incubated for 1 hour at RT. Samples were discarded, following 4 washes as described above, using Trisphosphate buffered saline (TPBS). Next, horseradish peroxidase (HRP) conjugated streptavidin p53 antibody (10 μg/ml HAF1355 (R&D)) was added to the wells and incubated at RT for 1 hour. After the plate was washed 3 times in TPBS, TMB substrate solution (50 μl each well, Thermo, (Cat. No. ES001-1L-K)) was added and incubated at 37° c. for 20 min. The reaction was stopped with 2M sulfuric acid (50 μl). The absorbance was measured at 450 nm with a spectrophotometer. Protein concentration was determined by dividing the absorbencies of each sample to the absorbance of Ab 421 samples.

DNA Binding Assay

For these experiments, a commercial p53/DNA binding kit of “R&D” (Cat-DYC1355-5 Lot-1273366FA) was used, in accordance with manufacturer guide lines. Briefly, 96 well plates are coated with anti-p53 antibody overnight. Cell extracts containing p53 are reacted with an oligonucleotide that contains a p53 consensus binding site (provided in the kit), labeled with biotin, in the presence or absenc.

e (NT) of test peptides. WT p53 is expected to bind this DNA binding site as well as to the antibody coating the test wells of the plate. Excess p53 and oligos were washed away and streptavidin-HRP was used to quantify the amount of oligos in the well, which is proportional to the DNA bound by p53. TMB assay was performed to determine HRP (ES001-1L-K) levels (450 nm).

Crystal Violet Assay

Cells were cultured in 96 wells plates with 2500-4000 cells/well in 0.1 ml and incubated overnight at 37° C. in order to adhere to the plate. Serial dilutions of different peptides (0.5 μg/ml) were added in 0.1 ml aliquots and the plates incubated for additional 48 h at 37° C. Then medium was removed and cell lysis was determined by staining the cells with crystal violet (0.5%) in methanol/water (1:4, v/v), 50 μl each well, for 10 min, followed by 3 washes with PBS. Afterwards, 10% acetic acid (50 μl) was added to each well and shaken for 10 min. Then, automatic plate reading was performed at 595 nm.

Immunofluorescence

Cells were cultured on cover slips overnight and then were treated with peptides using X-fect transfection. After 2 hour recovery, cells were fixed with 4% paraformaldehyde for 30 min at room temperature followed by 3 washes (PBS). Samples were permeabilized with 0.1% Triton (1% BSA in PBS) for 10 min RT followed by blocking (3 washes of 0.5% BSA in PBS), 5 min each wash. Cells were then probed with a mouse anti-p53 (DO-1) antibody diluted 1:500 for 1.5 hours, followed by blocking (3 washes of 0.5% BSA in PBS), 5 min each wash. Then cells were probed with goat anti-mouse Cy3 diluted 1:600 and DAPI diluted 1:1000 for 45 min. Samples were mounted with Elvanol.

Luciferase Assay

Construction of Luciferase Constructs

The oligonucleotide (RGC-W) that has the sequence 5′-TCGAGTTGCCTGGACTTGCCTGGCCTTGCCTTTTC-3′ (SEQ ID NO:362), and the oligonucleotide mutant RGC oligonucleotide (RGC-M) that has the sequence 5′-TCGAGTTTAATGGACTTTAATGGCCTTTAATTTTC-3′ (SEQ ID NO:363), are both derived from Kern et al. (Kern, S. E., et al., Identification of p53 as a sequence-specific DNA-binding protein. Science, 1991. 252(5013): p. 1708-11), and serve as a consensus binding sites for WT p53.

These motifs were cloned into the KPN and Eco53IK sites in pCLuc Mini-TK 2 Vector (NEB, Cat No. N0324S ). The Luciferase construct was used to assess transcriptional activation of p53 in test cells.

ChIP Analysis

Briefly, clones were cross-linked with formaldehyde (1% final concentration) at room temperature for 10 min. The formaldehyde was neutralized with 2.5M glycine (final concentration 0.25M) for 5 min. Cells were washed sequentially with 1 ml of ice-cold PBS, buffer I (0.25% Triton X-100, 10 mM EDTA, 0.5 mM EGTA, 10 mM HEPES, pH 6.5), and buffer II (200 mM NaCl, 1 mM EDTA, 0.5 mM EGTA, 10 mM HEPES, pH 6.5) and harvested by scraping. Cells were then resuspended in 0.3 ml of lysis buffer (1% SDS, 10 mM EDTA, 50 mM Tris-HCl, pH 8.1, 1× protease inhibitor cocktail (Roche Molecular Biochemicals, Indianapolis, Ind.) and sonicated 10 times (20 sec ‘on’ followed by 40 sec ‘off’) at the maximum setting (Biorupter, Diagenode, N.Y.) followed by centrifugation for 10 min on ice to produce 200-500 bp fragments. Supernatants were collected and diluted 10 times in the ChIP dilution buffer (1% Triton X-100, 2 mM EDTA, 150 mM NaCl, 20 mM Tris-HCl, pH 8.1) followed by immuno-clearing with 40 μl of pre-blocked protein A-sepharose (Santa Cruz Biotech) with 2 μg sheared salmon sperm DNA and pre-immune serum (1 μg of rabbit serum with 10 μl of 100 mg/mL BSA for 2 hour at 4° C. A sample was retained for the preparation of the input sample.

Immuno-precipitation was performed overnight at 4° C. with specific antibodies obtained from. After immuno-precipitation, 40 μl protein A-Sepharose (pre-blocked with salmon sperm DNA) were added and further incubated for another 1 hr. Precipitates were washed sequentially for 10 min each in TSE I (0.1% SDS, 1% Triton X-100, 2 mM EDTA, 20 mM Tris-HCl, pH 8.1, 150 mM NaCl), TSE II (0.1% SDS, 1% Triton X-100, 2 mM EDTA, 20 mM Tris-HCl, pH 8.1, 500 mM NaCl), and buffer III (0.25 M LiCl, 1% NP-40, 1% deoxycholate, 1 mM EDTA, 10 mM Tris-HCl, pH 8.1). Precipitates were then washed three times with TE buffer and extracted twice with 1% SDS, 0.1 M NaHCO₃. Eluates were pooled and heated at 65° C. for a minimum of 6 hour to overnight to reverse the formaldehyde cross-linking. DNA fragments were purified with a QIAquick Spin Kit (Qiagen, CA). Immuno-precipitation reactions were performed in triplicate using beads only as a non-specific control. Quantitative analysis of the active and repressive histone marks in the ChIP products from clones were assessed by quantitative real-time PCR. In order to normalize the efficiency of immunoprecipitation (IP), the normalization of chromatin IP was done using specific primers for necdin promoter region and 5′ region (which corresponds to a repressive chromatin region).

Cell Culture and Luciferase Reporter Assays

H1299 p53-null cells were cultured overnight and then transfected with the luciferase constructs using MaxFect Transfection Agent (Mediatech) according to the manufacturer's protocol. Prior to the transfection, cell medium was exchanged to OPTI-MEM.

The cells were treated with different peptides 24 hours after transfection. After additional 24 hours, growth medium was collected to 96 black plates: 40 μl for Cluc assay, and 20 μl for Gluc assay. Assay was performed using Turner BioSystems Modulus Microplate. Value was calculated by Cluc/gluc/NT (non-treated cells).

RT-PCR

RNA was obtained using Macherey-Nagel NucleoSpin RNA II Kit on cells pellet according to the manufacturer's protocol. Aliquots of 0.4-1 μg were reverse transcribed using Bio-RT 2000 (Bio-Lab) and random hexamer primers. Quantitative real-time polymerase chain reaction (QRT-PCR) was performed on an ABI 7300 instrument (Applied Biosystems) using PerfeCTa SYBR Green FastMix ROX (Quanta). RT-PCR primers used are presented in Table 1 (primers sequences are presented 5′ to 3′).

Phage Display Library

Phage display library used were commercially available phage libraries, generated by New England Biolabs (NEB). One library is of linear hepta-peptides (PhD-7), the other library is of linear dodeca-peptides (PhD-12) (CAT NOs.: PhD-7, E8100S; PhD-12, E8110S). The randomized peptide sequences in both libraries are expressed at the N-terminus of the minor coat protein pIII, resulting in a valency of 5 copies of the displayed peptide per virion. All of the libraries contain a short linker sequence between the displayed peptide and pIII.

Deep Sequencing

Prior to sequencing, a PCR reaction was performed with primers flanking the inserted libraries Forward-5′-NNNNNNNNCATGGAAAGATAGTG (SEQ ID NO:364) and Reverse-5′-NNNNNNNNCCTAAAACGATTTGTG (SEQ ID NO:365), first 8 bases of each primer are randomized and were incorporated as a mixture of all four bases. Randomization of first bases was introduced since the Solexa sequence equipment is incapable of sequencing repetitive sequences for the first few cycles. The PCR reaction yielded DNA in the required quantity 5 ug and length (about 120 bp) which includes the flanking primers and the cloned peptide library for Solexa deep sequencing.

Example 1: Calibration of Experimental Conditions

Choosing a p53 Protein Source

When choosing the protein source for phage display selection, several considerations are taken into account; the use of purified proteins is recommended since interaction of phage clones with different proteins in solution can give rise to nonspecific false positive peptides. The human full length p53 protein purified from SF9 cells (see above), was used in the following experiments (Accession No. CG3336). Therefore, an expression system of p53 in SF9 insect cell line infected by baculovirus (as detailed above) was used. A major advantage of p53 expressed in this system is that it already contains post translational modifications.

Conformation of Baculovirus-Expressed WT p53 and Mut-p53 Proteins

Initial experiments with the Baculo-p53 were made by using the nuclear extracts lysates of Sf9 cells expressing either WT p53, a hot spot full length mutant p53 (R175H), or temperature sensitive (ts) mutant p53 (V143A). SF9 cells were infected with viruses caring either one of the three expressing vectors. 48 hours after infection cells were harvested, nuclei extracted and the extracts were subjected to immunoprecipitation with: PAb1620, PAb240, ASPP2 (also named (P53-BP2)) and/or Bcl2 for 3 hours at 4° C. The immunoprecipitated p53 was detected by western blotting using the αp53-HRP Ab (Cat No. HAF1355 (R&D)). The results of this IP-Western experiment are shown in FIG. 2. As can be seen, the temperature sensitive (ts)-mutant p53 V143A (4° C.) and the WT p53 both bind well to the PAb1620 antibody, but not to PAb240. On the other hand, the mutant p53 R175H exhibits stronger binding to PAb240 than to PAb1620. This suggests that Baculo-expressed mutant p53 R175H assumes a conformation that is an intermediate between mutant and wild type p53. Bcl2 does not exhibit binding to either one of the p53 forms, whereas ASPP2 (P53-BP2) binds to all forms of p53 with approximately the same affinity. Therefore, it is concluded that ASPP2 and Bcl2 cannot be used as markers of p53 conformation under these experimental conditions.

Calibration of Solution Conditions

In order to reduce the relatively high residual binding of the mutant p53 R175H to the PAb1620 and to enhance the binding of WT p53 to that antibody, fine tuning of assay conditions was performed. The results are shown in FIG. 3 which shows a blot of the purified mutant p53 (R175H) and WT p53, extracted from nuclei of Sf9 cells infected with the corresponding baculovirus (as described above). The purified p53 was dissolved in the specified buffers (A-Tris-50 mM; B-Tris, NaCl 150 mM; C-Tris, NaCl, Triton 0.5%; D-Tris, Glicyn 0.5%; E-Na4O7P2 40-mM; F-GndCl 400 mM; G-GndCl 800 mM; H-Urea 1M; I-Urea 3M; IP-IP Buffer) and then immunoprecipitated with PAb1620 and PAb240 for 3 hours at 4° C. and subjected to western blotting using the αp53-HRP-Ab. As can be seen, solution (A) contains only 50 mM Tris. In this solution the binding of mutant p53 R175H to PAb1620 is only about 5% compared to that bound to PAb240. Addition of either 150 mM NaCl (B), 150 mM NaCl+0.5% Triton (C) or 0.5% glycine (D) enhanced the binding of mutant R175H to PAb1620. 3M Urea (I) reduced the binding of p53 mutant R175H to PAb1620, probably by causing denaturation of the protein. A lower concentration of urea, 1M (H), increased the binding of mutant p53 R175H (R175H p53) to PAb1620. 40 mM Na₄O₇P₂ (E) reduced the binding of R175H p53 to PAb1620 to the lowest level. Finally, in IP buffer the, R175H p53 remained PAb1620 negative; however in this buffer WT p53 showed strong PAb 240 binding and reduced binding to PAb1620, suggesting that IP buffer causes mild misfolding of the WT form. Hence, buffer containing Tris only is used for further experiments.

Example 2: Initial Screening of Phage Display Library and Selecting for Mut-p53 Reactivating Peptides

A phage display screen, using the R175H p53 protein, a single phd-12 phage library (NEB, Cat. No. E8110S) and selection with PAb1620 antibody was initially performed. 200 ng of R175H p53 were reacted with 10¹¹ phage for 1 hour to allow binding of presented peptides of the phage to the Mut-p53 (R175H). Next, beads cross linked to PAb1620 were added for an additional 1 hour to immunoprecipitate the entire complex. This panning procedure was repeated for three rounds, increasing the stringency of the selection after each round by reducing the amount of incubated Mut-p53: 1^(st) round 200 ng, 2^(nd) round 100 ng and 3^(rd) round 50 ng. Phages were eluted using purified WT p53 DBD, at a concentration of 2 μg/ml (p53 DBD (residues 94-293) was sub-cloned into pET-27b (Novagen)). The plasmid was transformed into E. coli BL21 (DE3) strain. Protein production was conducted following a procedure described for the mouse p53 DBD (Suad, O., et al., Structural basis of restoring sequence-specific DNA binding and transactivation to mutant p53 by suppressor mutations. J Mol. Biol., 2009. 385(1): p. 249-65). After each round of selection, tittering of the eluted phage was performed, to get an estimate of the number of phages that were selected (Table 2). The eluted phages were amplified by infecting E-coli, to yield about 10¹³ phage for selection in the next round. From the second round of panning, a control panning experiment was performed with PAb1620 only (without incubation with Mut-p53); this titer is indicative of the specificity of the panning.

As seen in Table 2, 100 infectious phage particles/μl were obtained in the first selection round and typical enrichment values between selection rounds, giving rise to higher enrichment in the first couple of rounds and then reaching a plateau in the third and fourth round panning. However, the number of phage eluted in both the specific selection panning reactions as well as in the nonspecific PAb1620 control panning reactions was similar. Such enrichment suggests that the phage may bind directly to the PAb1620 and not through interaction with the p53 R175H target.

In order to reduce background (nonspecific binding), additional pre-clearing steps and increasing pre-clearing time were introduced; however, the proportion of background binding remained high. Therefore, alternating selection steps during the phage display process were implemented, in order to reduce background binding. To this aim, different selection strategies at each selection round, while trying to minimize common nonspecific elements in the experimental system (and hence reducing binding to those nonspecific elements) were performed.

Since it is assumed that a prerequisite of conformational change of p53 is the binding of a peptide to p53, an additional selection step for WT p53 binding in between the PAb1620 selections was introduced. It was hypothesized that since PAb1620 would not be present in the second panning round, the phage binding directly to it would be eliminated. Moreover, since a prerequisite of any functional peptide is binding to p53, peptides preferentially binding to the WT form are expected to stabilize this conformation. The first and third rounds of panning were similar to the previous experiment. In the second selection round, however, a selection for phage binding for WT-p53 (His tagged) was performed, and the p53/phage complex was immunoprecipitated using nickel beads (which bind to the His tag). The titer of the eluted phage was evaluated after each selection round. As shown in Table 3, 10-fold enrichment was achieved in the elution of phage when the second cycle was compared to the first. Although this may be considered a bit low by phage display standards, the reason for this relatively low enrichment is probably the use of different selection strategies in each round of panning, increasing the specificity but on the other hand reducing the overall yield of selected phage. The enrichment from the second selection round to the third was in the order of 100 fold, indicating a marked increase in phage enrichment, compared to the previous factor of 10. This marked increase is due to the repeated PAb1620 selection. Importantly, the number of phages after the third round was in the order of 10⁵, whereas with the control PAb1620 it was 4×10³. Therefore, the nonspecific control (i.e., background), constitutes only about 5% of the total selected phage.

Example 3: Method for Screening, and Identifying Mut-p53 Reactivating Peptides

In order to screen, identify and isolate specific p53 reactivating peptides, a method which uses a combination of different and complementary selection strategies was devised and performed.

In this example, three selection strategies were combined. The first selection strategy relies on the reactivity with PAb1620, as described above. The second selection strategy is based on the binding of WT p53 to its consensus DNA sequence motif: p53 responsive element (p53-RE). The binding of p53 to its consensus DNA in-vitro has been extensively demonstrated [Joerger, A. C., M. D. Allen, and A. R. Fersht, Crystal structure of a superstable mutant of human p53 core domain. Insights into the mechanism of rescuing oncogenic mutations. J Biol Chem, 2004. 279(2): p. 1291-6). Accordingly, two complementary oligonucleotides were designed to produce dsDNA (after annealing). These oligonucleotides contain two tandem copies of a p53-RE consensus sequences: one consensus sequence is the perfect consensus binding site, deduced from binding experiments (AGACATGCCCAGACATGTCC (SEQ ID NO:339)) and the other sequence is a p53 DNA binding site, derived from the p21 promoter (GAACATGTCCCAACATGTTG (SEQ ID NO:328)), which is located downstream to the first consensus sequence (FIG. 4). In addition, two restriction enzyme sites (HindIII (AAGCTT (SEQ ID NO:341)) and EcoRI (GAATTC (SEQ ID NO:342)), which enable a more specific elution step after selection were further introduced. One oligonucleotide strand was also labeled with biotin, to allow immunoprecipitation of DNA/p53/phage complex with streptavidin coated beads. FIG. 4 shows a schematic sequence of the p53-RE oligonucleotide and the sequence elements thereof. The sequence of the upper strand oligonucleotide is:

(SEQ ID NO: 361) Biotin-5′- CTGCTGAAGCTTCGAATTCCT AGA

CCCAGA

TCC TACTGCT GCTGCTGCTGCTGCTGC GAA

TCCCAA

TTG CTGCTGCTGCT GCTG-3′.

In a selection procedure performed using the DNA binding strategy (as detailed below), 0.5-3 pmol of the biotin-p53-RE oligonucleotide was reacted with 200 ng of purified WT p53 for 1 hour to allow binding. 10¹⁰ phage from either PhD-7 or PhD-12 phage libraries were then introduced for an additional hour. Next, streptavidin coated agarose beads were added for 30 minutes. 5-12 washing steps were then performed, followed by elution performed by adding either the restriction enzymes or an excess of non-biotinylated DNA for 30 minutes. These precautions would reduce selection of phage binding to DNA, biotin and streptavidin.

The third selection strategy is based on the SV40 large T (LT) antigen. The binding between p53 and SV40 LT is considered to be very strong. Therefore, p53 has to be folded properly to form the binding epitope platform to SV40 LT. To this aim, Sf9 cells were infected with baculovirus encoding for SV40 LT. Cells were lysed and the SV40 LT was isolated using protein-A beads cross-linked to PAb 419 (antibody specific for SV40 LT, (Abcam-ab1684)). Beads were washed several times, and then used for phage display selections. The panning procedure for SV40 LT binding was similar to the conformation based strategy, except that instead of using PAb1620 beads, PAb 419-SV40 LT beads were used for the selection.

A combination of all three selection strategies in alternating rounds yields the best results, since each cycle gradually increases the percentage of phage that harbor the desired specific peptides, while reducing non-specific background. A schematic illustration of the method of identification and selection is illustrated in FIGS. 1A and 1B.

Phage display screening was performed in parallel with PhD-7 and PhD-12 phage peptide libraries. Alternating cycles of phage selection, using a different immobilized platform (PAb1620, p53-RE DNA or SV40 LT) at each step were performed. Table 4 shows the different selection routes taken to produce enriched phage libraries, and specifies the titer values after each round of selection. By using such different combinations of selection platforms (e.g. PAb1620 followed by p53 consensus DNA followed again by PAb1620, or SV40 LT followed by PAb1620 followed by SV40 LT), as well as the 2 different phage libraries, a panel of sub-libraries was obtained, that could then be compared after sequencing. After 3 cycles of selection, over 60 different pools (sub-libraries) containing a high proportion of Mut-p53-reactivating phage (Table 4) were obtained.

Example 5: Selected Phage Pools Induce Binding of Mut-p53 to PAb1620

To determine whether the phage display selection method as performed above can enrich for phage that reactivate Mut-p53, the ability of the phage pools obtained after 3 cycles of selection to induce the binding of either full length R175H Mut-p53 (BD Pharmingen, Cat. No. 556439), or the recombinant R249S p53 DBD (249 DBD) proteins to PAb1620 was tested. To reduce the undesirable effect of contaminating phage that exhibit direct binding to PAb1620, a pre-clearing step was included whereby the phage pool was first incubated with PAb1620 only, before being added to the test reaction. Beads covalently cross-linked to PAb1620 were incubated with purified mutant p53 R175H in the presence of phage obtained by phage display selection with either Mut-p53 R175H (175) or Mut-p53 R249S (249), either without or with prior pre-clearing step performed by incubation of the phage pool with PAb1620 beads. Non selected phage (ns) were used as control. Incubation was performed for 3 hours at 4° C. Bound p53 was visualized by western blot analysis using antibody against p53. As can be seen in the results presented in FIG. 5, some of the selected phage pools indeed induced binding of Mut-p53 to PAb1620, as compared to no phage or non-selected input phage (ns).

Example 6: Selected Phage Pools Induce Binding of Mut-p53 to p53 Consensus DNA

To further test whether the selected phage pools can facilitate the binding of Mut-p53 to p53 consensus DNA binding element, biotin-labelled oligonucleotides corresponding to the p53 responsive element consensus (p53-RE) biotin-AGACATGCCCAGACATGTC CTTATAGACATGCCCAGACATGTCC (SEQ ID NO:366) or control oligonucleotides mutated in key residues crucial for p53 binding (Con-RE biotin-AGAaATGCCCAGA aATGTCCTTATAGAaATGCCCAGAaATGTCC (SEQ ID NO:367), were immobilized by reacting these oligos with streptavidin coated beads. The p53-RE or Con-RE beads were incubated with either WT p53 DBD or mutant 249 DBD, together with the phage pools obtained after 3 cycles of selection. Streptavidin coated beads bound either to p53-RE-DNA or Con-RE-DNA oligonucleotides, labelled with biotin, were incubated with purified WT p53-DBD or mutant p53 R249S-DBD in the presence of phage obtained by phage display selection with Mut-p53 R175H (175), clone 27 (LPNPPER, SEQ ID NO:328) (a single clone isolated from the R175H selection), pools #69 and #94, selected with WT and Mut-p53 R175H using combinations of T-AG and PAb1620 at alternating selection rounds. Non selected phage (NS) were used as control. Incubation was for 3 hours at 4° C. Bound p53 was visualized by western blot analysis. As can be seen in the results presented in FIG. 6, the WT p53 DBD bound to p53-RE better than to the Con-RE, as expected. The 249DBD did not bind to the p53-RE, consistent with its known loss of sequence-specific DNA binding ability. Importantly, the selected phage pools were capable of inducing the binding of Mut-p53 to the p53-RE, demonstrating that they are indeed capable of reactivating and restoring the lost function of Mut-p53.

Example 7: Deep Sequencing of Selected Phage Pools

Next generation sequencing, which greatly increases the effectiveness of phage display, allowing extraction and analysis of the entire selected peptide repertoire, with fewer selection cycles was performed. Eight phage pools were selected for deep sequencing using criteria of increased enrichment between selection rounds and functional activity. Prior to sequencing, a PCR reaction was performed with primers flanking the inserted libraries: Forward-5′-NNNNNNNNCATGGAAAGATAGTG (SEQ ID NO:364), and Reverse-5′-NNNNNNNNCCTAAAACGATTTGTG (SEQ ID NO:365), the first 8 bases of each primer are randomized and were incorporated as a mixture of all four bases. Randomization of first bases was introduced to improve sequencing efficiency and accuracy. The PCR reaction yielded DNA in the required quantity 5 μg and length (about 120 bp), which includes the flanking primers and the cloned peptide library for Solexa deep sequencing.

The deep sequencing yielded a database of 36 million reads. 95% of the sequences contained the primer sequences used in the PCR when extracting the libraries. Next, a preliminary bioinformatics analysis of the data was performed. This analysis included the removal of sequences that do not contain the original primers, removal of sequences that are not in the correct reading frame, segregation of the database into the original 12 amino-acid and 7 amino-acid libraries according to insert length, and finally counting of unique sequences and sorting them according to number of appearances in the database. It was found that most sequences appeared only once or twice in the database, presumably corresponding to background phage. 12 reads were defined as a cutoff, beneath which the enrichment of sequences was considered to be insignificant. The DNA sequences in the database were then translated into amino acid sequences.

As an internal quality control, the sequences and their abundance as the percent from the total library between the two strands that were sequenced from opposite directions and therefore contained a different primer at their 5′ were compared. The comparison showed that the sequences and their abundance was similar between the two strands, indicating that the obtained sequence database is valid.

Table 5 shows a list of peptide sequences obtained from the deep sequencing database of 5′ strands. This database contains 10⁷ sequences in total, after filtering irrelevant sequences. A cut-off counting and translation was then performed. The column (#Reads) shows the number of times the sequence repeats in the described database and therefore corresponds to the enrichment of that specific sequence. Since the bioinformatics analysis was performed on DNA sequences, and individual peptides can be encoded by several different DNA sequences because of the genetic code degeneracy, there are quite a few peptides that appear in the table more than once. If a certain peptide is encoded by different DNA sequences, it means that it was selected independently within different phage clones.

Alternatively, a number of DNA sequences coding for the same peptide could be a result of sequencing errors: however, in this case it would be expected that the result of such a mistake would be in a random base and therefore not enriched in a high number of reads. Therefore, DNA sequences that were under 30 reads in the #Repeats count were excluded. The column (#Repeats) shows the number of DNA sequences coding for the same peptide sequence, and is therefore a further indication of the specificity and strength of the selection.

As seen in Table 5, the sequences could be segregated into their two libraries of origin. The peptide sequence is depicted in the middle column and the sequences are sorted in descending order according to the number of reads that corresponds to the enrichment in each library. The 12aa library was found to be dominated by a single sequence—KPPDRLWHYTQP (SEQ ID NO:322), that makes up almost 20% of the total number of sequences. The 7aa library is more diverse and contains many more sequences, but with lower enrichment values.

Table 5 presents the analysis of deep sequencing data base—sequences are divided into to their two libraries of origin, the peptide sequence is depicted in the middle column and the sequences are sorted in descending order according to the number of reads that corresponds to the enrichment in each library. The column (#Repeats) shows the number of DNA sequences coding for the same peptide sequence.

Example 8: Bioinformatics Motif Analysis of the Deep Sequencing Database

Next, a more comprehensive bioinformatics analysis was performed in order to identify consensus motifs. Such motifs could be elucidated in several ways. First, comparison between peptide sequences identified in the 12aa and the 7aa libraries. The appearance of common motifs in both libraries would support the strength of such a motif since it was clearly selected in two completely independent experiments. Secondly, the abundance of a certain amino acid in a particular position and its similarity to other amino acids in the same position of the motif can serve as an indication for the significance of such amino acid in this particular position. Thirdly, the position of a motif may be of critical importance to its function: a short motif can shift along a longer peptide sequence with variability in other amino-acid sequences and the distance from the free N-terminus of the peptide may inform on significance to its activity. An algorithm was developed to check the amino acid sequence in a growing window of peptide length as follows:

1. scoring each peptide, integrating the number of different nucleotide sequences that translate into the same peptide with the occurrences of each such type of nucleotide sequence;

2. clustering the different peptides, scoring the sequence similarity between different peptides; and

3. identifying groups of related peptide sequences and extracting a consensus therefrom.

Candidate peptides were those with the top occurrences ≥0.2%: 40 from the 7aa library, and 32 from the 12aa library. These could be clustered into 40 groups by their Blastp similarities and occurrence of a short amino acid (aa motif). Most groups included a single peptide, but 9 groups included 2-13 peptides, and 6 of these groups included both 7aa and 12aa peptides.

The groups were transformed into block multiple alignments, with the % occurrences being the sequence weights. The blocks were used to query the 7aa and 12aa peptide-clustered sequence files, and the top results were again transformed into blocks in the same way. In some blocks, but not in all, results from the two libraries were similar to each other.

The deep sequencing output (i.e. creation of database of millions of peptide sequences as compared to hundreds of sequences by conventional sequencing) enabled a much more detailed and comprehensive analysis of consensus motifs. Overall, about 130 motifs of significantly enriched sequences were identified; most of these peptide motifs are represented by several DNA sequences and 16 of these motifs are shared between both the 7aa and 12aa libraries. FIG. 7 shows several such motifs. Some of the motifs resulted from combining overlapping sequences and therefore are longer than the original peptide libraries.

Example 9: Synthesis of Peptides

From the obtained list of peptide motifs identified as described above, 128 peptides were chemically synthesized by PEPTIDE 2.0 at crude purity taking advantage of a 96 well format. This semi high throughput synthesis enabled a relatively low cost of each peptide. Table 6 below lists the peptides synthesized. This list also includes some peptides derived from proteins that are known from the literature to interact with p53. The list also includes 10 peptides synthesized in two versions, both without and with a poly arginine C-terminal addition. This poly-Arg addition was reported to enable the crossing of peptides across cell membranes. This allows the evaluation of both the ability of the poly Arg C-terminal addition to enable peptide delivery into the cells and whether it interferes with the activity of these particular peptides in-vivo. The poly Arg may include 0-10 Arg residues and is designated as R₀₋₁₀.

Differences between the chemically synthesized peptides and the peptides that were selected from phage display libraries may occur. In particular, the selected peptides were presented in the context of the phage as fusion proteins with the pIII phage coat protein. Therefore, this transition to synthetic peptide is not trivial, and it is known that in some instances peptides shown to be active when presented on phage lose their activity when the same sequence is synthesized as a free peptide.

Example 10: Functional Screening of Lead Test Peptides

Several alternative and complementary methods to screen the lead peptide candidates for conformational and functional effects on Mut-p53 were used. Since no information regarding the penetration of each test peptide across cell membranes was known, in-vitro based assays for evaluation were first performed: ELISA for assessment of p53 conformation and sequence-specific DNA binding of p53. Subsequently, the peptides' activity was examined in live cells by viability assays, p53 transcriptional activity on a luciferase reporter gene, and examination of p53 target genes in-vivo. Combination of these assays (all performed in a 96 well format) allowed the identification and validation of the peptide's effects on different p53 activities and their ability to confer such ability to Mut-p53 proteins.

Screening Peptides for Effect on p53 Conformation

The first screening strategy was based on ELISA. A version of sandwich ELISA was used to examine the effect of the lead test peptides on p53 conformation. To measure the conformational effect of the peptides on Mut-p53, a micro-titer plate was coated with PAb240, PAb1620 or pAb421 (as a positive control), and then the reactivity of p53 to these antibodies was examined. WT p53 served as a positive control for reactivity with PAb1620, and Mut-p53 served as a negative control. To examine the effect of a tested peptide it was added to a solution containing Mut-p53 and change in reactivity to either Ab was tested. If after addition of a peptide an increased reactivity of Mut-p53 towards PAb1620 and a decreased reactivity to PAb240 were observed, it indicated that the tested peptide has reactivated WT conformation of Mut-p53. Several ELISA experiments using different cell extracts were performed. The results are presented in FIGS. 8A-B, which show a representative experiment performed on an extract of H1299 cells stably overexpressing Mut-p53, (R175H p53). Extracts were prepared at 750 ng/μl concentration in standard immunoprecipitation buffer at a physiological pH and salt concentrations and supplemented with 3% BSA for blocking, and then reacted with different peptides at a concentration of 50 ng/ml for 2 hours. Plates were coated with the various antibodies (Abs) overnight, washed, blocked, and cell extracts (with or without peptides) were added for an additional 2 hours. After removal of extracts, plates were washed and incubated with the αp53-HRP conjugated Ab for the detection of p53 levels. Finally, a TMB (substrate of HRP) assay was performed and optical density was determined at 450 nm (as described above). MCF7 and H1299-Mut-p53 (ts) A135V (Zhang, W., et al., A temperature-sensitive mutant of human p53. Embo J, 1994. 13(11): p. 2535-44) cells were used as positive controls for the WT p53 conformation (1620/240 ratio equals or exceeds 5:1). The H1299-R175H p53 extracts, while exhibiting more mutant p53 conformation, still maintained reactivity to PAb1620 (1620/240 ratio is 1:2) of PAb1620 or PAb240 over PAb421. However, when discussing the outcome of the analysis, the PAb1620/PAb240 calculated ratio, which better captures the extent of conformational change is referred to. To examine whether this is background binding to the antibody or actual WT folding conformation, increasing levels of denaturation were induced by heating the extracts for different time lengths, monitoring their reactivity to PAb1620 and PAb240. As seen in FIGS. 8A and 8B, increased heat treatment induced an increase in reactivity with PAb240 and a decrease in reactivity with PAb1620, indicating that the R175H p53 in these extracts remained partly in WT conformation under these experimental conditions. Notably, after incubation with some of the tested peptides, increased reactivity of R175H Mut-p53 towards PAb1620 and decreased reactivity towards PAb240 was detected. This was the case, for example, with peptides 24, 36, 47, 60, 68 (Table 6), indicating that these peptides elicit a conformational change in mutant p53 protein.

Screening of Peptides for Effect on Mut-p53 Binding to p53-RE DNA.

To measure the effect of the tested peptides on DNA binding of Mut-p53, a commercial ELISA kit, (R&D Systems DYC1355-5, Lot-1273366FA), was used as a high-throughput assay to quantify p53 activation. This kit uses a 96-well plate format. The kit was used according to manufacturer's instructions. Wells were coated with anti-p53 antibody overnight. Cell extracts containing p53 were reacted with a biotin labeled oligonucleotide containing a p53 consensus binding site (included in the kit). WT p53 is expected to bind this oligo as well as the antibody coating the wells. Excess p53 and oligo were washed away in wash buffer (0.05% Tween 20 in PBS, pH 7.2-7.4; R&D Systems, Catalog #WA126). Then, streptavidin-HRP (R&D Systems, Part 890803, provided in the kit) was added for 15-45 min to quantify the amount of oligo in the well, which is proportional to the DNA bound by p53. If the addition of a peptide to Mut-p53 extracts increases ELISA reading compared to background, this peptide is considered as functionally effective and may be selected for further analysis. FIG. 9 shows a representative experiment: similarly to conformation ELISA, cell extracts were incubated with biotin-p53-RE either in presence or absence (NT) of test peptides. As with the conformational screening, MCF7 and the H1299-Mut-p53 (ts) A135V cells served as positive controls for WT p53. Extracts were added to the wells coated with αp53-Ab, and after several washing steps, streptavidin-HRP was added for 1 hour, and then plates were washed again and TMB (substrate to HRP) assay was performed. As can be seen in FIG. 9, H1299-R175H p53 extracts exhibited some background binding to the p53-RE oligo, which was further reduced by non-labeled competing oligo. Positive controls showed a 3-4 fold higher signal compared to the background. Several peptides appear to elevate the binding of H1299-R175H p53 extracts to p53-RE DNA, for example: 68, 75, 83, 93, 97.

Binding of Peptides to WT p53 and Mutant p53.

To measure the binding of peptides to Mut-p53 and WT p53, a commercial ELISA kit from “TAKARA” (MK100 Lot AK401), was used as a high-throughput assay to quantify the binding of different peptides to proteins or antibodies. The kit was used according to the manufacturer's instructions. The wells were plated with the peptides by performing a chemical reaction attaching the C-terminus of the peptide to the plate.

Recombinant WT p53 or Mut-p53 R175H at a concentration of 10 ng/ml was dissolved in PBS and blocking buffer and then added to the peptide coated plates for 2 hours. Soluble peptides were added to the corresponding wells to serve as a competition control indicating the specificity of peptide binding to p53 (+comp) and p53-RE DNA oligo was added to other wells (+DNA) to examine whether it affects the binding of peptides to p53. After removal of recombinant protein, plates were washed and incubated with the αp53-HRP conjugated Ab to quantify p53 levels. Finally a TMB (substrate of HRP) assay was performed and optical density was determined at 450 nm. FIG. 10 shows a representative experiment performed with the corresponding peptides and antibodies. As seen, wells were attached with αp53 monoclonal antibodies to serve as internal controls of the assay; PAb1801 binds both p53 forms as expected; PAb1620 is specific to WT p53 and PAb240 is more reactive with the mutant form. The (blocked) wells were not coated with peptides and pep76 is control peptide sequence. As can be seen, most peptides shown in the figure bind with higher affinity to the recombinant WT p53 as compared to the mutant p53.

The Effect of pCAP on Mut-p53 Binding to its Responsive Elements in Live Cells.

Next, it was examined whether p53 can also bind to chromatin of its target genes. Using chromatin immunoprecipitation (ChIP) assay, it was examined whether pCAPs can restore the Mut-p53 DNA binding ability to p53 response elements (p53-RE). Breast carcinoma BT-549, endogenously expressing mutant p53^(R249S), were treated for 5 hour with a mix of 3 pCAPs; 250, 308 and 325. Cells treated with a mix of control peptides served as a negative control. Then cells were fixed and DNA was sheared by sonication. The DNA cross-linked to p53 was immunoprecipitated using polyclonal anti p53 antibody. DNA was purified and then p53 responsive elements of different p53 target genes were quantified using different primers in the qPCR reaction. Results were normalized to total DNA input. As a negative control, extracts were immunoprecipitated with beads without antibody (Beads). As seen in FIG. 11, the binding of chromatin to the control beads was at a basal level of 0.005% of the input DNA. pCAP mix did not increase the binding of p53 to a non-specific genomic DNA control sequence, but p53 binding to responsive elements in PUMA, p21 and CD95 genes was increased 2.34, 9.78 and 4.54 fold, respectively, by pCAPs compared to control peptides.

Screening Peptides for Effect on p53 Transcriptional Activity

As additional screening strategy used to identify reactivating peptides was performed in vivo and is based on a reporter gene assay. It measures p53 transcriptional activity by quantifying the activity of a reporter gene, placed under the control of a promoter containing 17 repeats of a p53 consensus binding site (RGC). The luciferase assay is performed on living cells and therefore provides an indication on the effect of test peptides on Mut-p53 function in the context of intact cells. An RGC-based promoter cloned upstream of a secreted luciferase reporter (TK-RGC-luc) (New England Biolabs (CAT. NO. N0324S)) was used, since it does not require lysis of the cells and allows the use of a 96 well format.

FIG. 12 shows a representative luciferase assay experiments that were performed to assess the ability of peptides to restore transcriptional activity to mutant p53. For the in vivo luciferase based screening, H1299 cells were used. Transient transfection of these p53^(−/−) cells was performed with vectors expressing WT p53, R175H p53, R249S p53 or empty vector as control (Suad, O., et al., Structural basis of restoring sequence-specific DNA binding and transactivation to mutant p53 by suppressor mutations. J. Mol. Biol., 2009. 385(1): p. 249-65). Cells were also co-transfected with TK-RGC-luc (CAT. No. NEB, N0324S). 24 hours after transfection, cells were treated with the test peptides. 48 hours after transfection, a sample of the culture medium was taken for bioluminescence measurements. As can be seen in FIG. 12, in the non-treated samples, transfection of WT p53, (positive control), induced transcription from TK-RGC-luc by 20-30 fold as compared to TK-RGC-luc alone. When examining the peptide treated samples, it is seen that the peptides had no significant effect on WT p53 activity; this is an encouraging result, since peptides greatly increasing WT p53 activity are expected to have toxic effects on normal cells. Two of the tested peptides, namely pCAP-68 and pCAP-75, induce transcription from TK-RGC-luc in the presence of R175H p53 and the R249S p53.

Screening Peptides for Effect on Viability of Mutant p53 Expressing Cells

An important indication for the reactivating peptides activity is their effect in-vivo on cancer cells that express Mut-p53. In particular, reactivating peptides that can cause specifically Mut-p53-dependent death of cancer cells, with minimal toxic effects on normal cells are desired. A crystal-violet based viability assay, in which crystal-violet is employed to stain cells that adhere to the plate and therefore the amount of dye is proportional to cell number was used to determine the effect of the various test peptides on Mut-p53-dependent death. The crystal-violet assay is straightforward, fast, reliable, inexpensive and does not require a complicated preparation of samples.

Cells were plated in 96-well plates, at calibrated density that allows them to grow for 48 hours without reaching confluence. Peptides are added 6 hours later. Different concentrations of etoposide (cytotoxic drug) were used as positive control for cell death and as a standard reference curve to assess the effect of tested peptides. 48 hours after treatment, cells were washed with PBS to exclude dead cells and debris, and cells that remained attached to the plate were stained with crystal-violet for 30 minutes. Crystal-violet was removed and cells were washed with PBS 4 times to eliminate remains of crystal-violet. Then, the stained cells were dissolved in 10% acetic acid and plates were taken for optical density measurement at 595 nM (specific to crystal-violet).

FIGS. 13A and 13B illustrate a representative experiment of screening performed on 128 synthesized peptides. In this experiment, WI-38 fibroblasts were used. These cells express endogenous WT p53 and were further infected with a virus expressing either mouse Noxa shRNA, as a nonspecific control or the R175H p53 mutant for stable overexpression of mutant p53. Both of these sub-lines (mNoxa or R175H p53) were seeded at 3000 cells per well and treated as described above. The optical density reads (595 nm) reflect the number of cells in the plate after treatment, normalized to the non-treated samples that are considered as 100% viable. As seen, although WI-38 cells are relatively resistant to killing, the increasing concentrations of etoposide serve as a good positive control for cell death and growth arrest with the highest concentration reducing cell number by 50% after 48 hours.

Several of the tested peptides indeed caused a significant reduction in cell numbers; this reduction was mutant p53 dependent, since it was much more prominent in the R175H p53 expressing cells as compared to mNoxa-i control cells. These peptides include, for example, pCAP-36, pCAP-46, pCAP-47, pCAP-60, pCAP-97. On the other hand, some peptides were found to have a toxic effect on both cell sub-lines; one example is pCAP-68. Similar assay was performed on several different Mut-p53-expressing human cancer cell lines, the results for the different peptides are summarized in Table 7.

Example 11: Homology of Lead Peptides to Sequences of Known p53 Binding Proteins

After performing the functional screen of peptide motifs predicted by phage display, 20 peptides were identified that exerted functional effects on mutant p53 in a variety of assays and cell lines. Next, the similarity of these peptides to sequences of human proteins in general and to proteins known to interact with p53 in particular was examined, since high similarity to proteins interacting with p53 can serve as an indication to the biological significance of a particular motif and can provide validation of the assumption that the peptides selected under artificial in-vitro conditions can indeed interact with p53. Moreover, the protein structure and surrounding sequence might be helpful in designing improved peptides that are based both on selection and rational design. To find similarities between peptide sequences and known human proteins, the BLAST (Basic Local Alignment Search Tool) algorithm was used. The peptide motifs were introduced as query sequences against a sequence database containing human protein sequences. BLAST finds sub-sequences in the database that are similar to subsequences in the query. The main idea of BLAST is that there are often high-scoring segment pairs (HSP) contained in a statistically significant alignment. BLAST searches for high scoring sequence alignments between the query sequence and sequences in the database using a heuristic approach that approximates the Smith-Waterman algorithm. Based on the similarities between the peptide motifs and known human proteins and structural data of these proteins, a list of new peptide sequences was designed (shown in Table 8 below), in which amino acids similar to peptide motifs are flanked by other amino acids derived from the protein sequence either flanking the motif or from structural elements in physical proximity to the homologous motif according to 3-dimensional crystallographic data.

Over 70 different proteins with varying degree of similarity to selected peptide motifs were identified. Many of these proteins had been shown previously to physically interact with p53, while others were reported to be involved in the p53 signaling pathway, either upstream or downstream of p53. Several motifs were found to have a very high degree of homology to known p53 interacting proteins; pCAP-97 (WNHHHSTPHPAH, SEQ ID NO:10) for example has 100% homology to RAD9A (with a p-value of 10⁻⁸) which was shown to interact and activate p53; pCAP-60 (SFILFIRRGRLG, SEQ ID NO:302) and pCAP-63 (HNHHHSQHTPQH, SEQ ID NO:226) have 90% homology to GAS2 protein sequence (KILFIRLMHNKH, SEQ ID NO:369) in which these motifs are separated by two amino acids (amino acids similar to peptide motifs are highlighted in bold letters).

Several alternative and complementary methods to screen lead peptide candidates for conformational and functional effects on Mut-p53 were employed. For increased penetration of peptide across cell membranes each peptide contains 3-6 Arginine residues either as part of its sequence or added either at its N-terminus or its C-terminus. 40 peptides were also conjugated to myristoil fatty acid (myr) for enhanced fusion with cell membranes that would potentially lead to better delivery into cells. In-vitro based assays for evaluation were first performed, such as ELISA for assessment of p53 conformation and sequence-specific DNA binding of p53. Subsequently, the peptides' activity was examined in live cells by viability assays, p53 transcriptional activity on a luciferase reporter gene, and examination of p53 target genes in-vivo. Combination of these assays (all performed in a 96 well format) allowed the identification and validation of the peptides' effects on different p53 activities and their ability to confer such ability to Mut-p53 proteins. As seen from Table 8, 12 peptides were found to have a total activity score above 30; all of these 12 peptides were shown to be effective in a variety of different assays including p53 conformation and sequence-specific DNA binding, reduction in viability of Mut-p53 expressing cells and activation of p53 target genes. Some of these lead peptides, which have a core motif derived from phage display with added sequences of known proteins (pCAPs 201-326) showed a significantly increased effect compared to peptides derived from phage display alone (pCAPs 1-180), while others were comparable to pCAPs 1-180.

After careful examination of peptide sequences that have shown the most significant effect in a combination of the assays, it was found that the lead peptides can be classified into several major groups, according to their consensus motifs. The consensus motifs consist of at least 3 consecutive amino-acids, which hypothetically form a sequential or conformational binding site for p53 mutants. These consensus motifs were found to be HSTPHP, FPGHTIH, IRGRIIR, LPNPPER, SFILFIR, HANLHHT, YPTQGHL, WNHHHSTPHP, TLYLPHWHRH, YRRLLIGMMW, IRILMFLIGCG, SFILFIRRGRLG, LRCLLLLIGRVG, SWQALALYAAGW, IRILMFLIGCGR, glrgrriflifs, HSSHHHPVHSWN, LRCLLLLIGRVGRKKRRQ (SEQ ID NOs:314, 268, 282, 328, 376, 298, 377, 378, 253, 20, 379, 302, 275, 380, 273, 381, 280 and 382, respectively).

Effect of Test Peptides on p53 Target Genes

The WT p53 protein works primarily as a transcription factor. Upon activation by different forms of stress it is accumulated, binds to its responsive elements in many target genes and trans-activates their transcription. Proteins that are the products of these target genes execute their functions; transactivation of p21, for example, leads to growth arrest, whereas transactivation of PUMA would lead to apoptosis. Therefore one of the most important indications to p53 functional activation is the induction of its different target genes. The effect of various test peptides on p53 target genes was therefore tested in-vivo.

For the in vivo functional screening, several experimental systems were used. One system is based on H1299 cells, which are p53 null and are widely used for p53 research. H1299 cells stably transfected with Mut-p53 (ts) A135V were used. This form of p53 is a temperature sensitive mutant, which has a mutant conformation at 37° C. and a WT conformation at 32° C. FIG. 14 shows a representative experiment. In essence, the cells were plated in 12-well dishes, the indicated peptides were added directly to the medium at a concentration of 5 ug/ml, and cells were then either moved to 32° C. or returned to 37° C. 18 hours later cells were harvested, followed by extraction of RNA, cDNA synthesis and real time PCR analysis. The expression level of 3 representative p53 target genes was examined; p21, PUMA and Mdm2. Expression of genes in H1299-ts at 37° C. is considered as background level and all results are normalized to it, and also to the GAPDH housekeeping gene. Expression of genes in H1299-ts at 32° C. represents WT p53 conformation and therefore serves as a positive control. As can be seen, temperature shift to 32° C. greatly increased expression of all 3 target genes.

As seen in FIG. 14, the negative control peptide pCAP-76 did not cause induction of p53 targets. Several tested peptides indeed caused a significant increase in the expression of p21, PUMA and Mdm2. This was the case for pCAP-130, pCAP-135, pCAP-142, pCAP-144 and pCAP-148. These peptides induced transcription of target genes by 2-4 fold, compared to 9-11 fold of the positive control, authentic wild type p53. The fact that treatment with peptides induced all three genes but had no effect on expression of these genes in control H1299 (p53^(−/−)) cells implies that this induction is p53 dependent.

Since delivery of peptides is a major obstacle in their use as therapeutic agents, different approaches were taken overcome this obstacle. First, based on the tested lead sequences, short peptide sequence motifs (up to 6 amino acids) were elucidated and synthesized, since these small peptides could cross cell membranes by diffusion. A second approach was to synthesize tested peptides with a polyarginine C-terminal tail to facilitate their active uptake by endocytosis-based mechanisms.

Addition of a poly arginine tail to peptides dramatically increases the solubility of peptides with a high content of hydrophobic amino acids. In some cases it also significantly increased the activity of the peptides both in-vitro and in-vivo; pCAP-25 for example was insoluble in DMSO at a concentration of 10 mg/ml and showed no effect on p53 activity when tested either for conformational change or viability. Whereas pCAP-68 which has the same amino acid sequence with the addition of the 9R tail caused a significant shift in Mut-p53 conformation towards PAb1620, as well as massive cell death. Lead peptides were further subjected to rigorous examination of effects on cell viability in a Mut-p53 specific manner.

Experiments using different cancer cell lines expressing endogenously different p53 mutant isoforms were performed. FIGS. 15A and 15B illustrate two representative experiments performed on MDA-MB-231 (FIG. 15A) and SKBR3 (FIG. 15B) breast cancer cells expressing Mut-p53 with mutations at positions 280 or 175, respectively, within the DNA Binding Domain (DBD). To examine the peptides' specificity for Mut-p53, the control used was such cells with a knockdown of Mut-p53 (shp53). As seen in FIGS. 15A and 15B, many of the tested peptides showed a reduction in cell viability in a Mut-p53 specific manner, with significant readings of 30%-80% relative to the 100% viability represented by non-treated Mut-p53-expressing cells. Some peptides show some degree of a toxic effect on cell viability in general, as seen in the shp53 cells. For example pCAP-155 exhibited a 30% to 40% reduction in viability in the two shp53 infected cell sublines. Furthermore, it is also seen that some peptides show specific reduction in cell numbers in particular cell types compared to minimal activity in others. pCAP-146 for example caused a significant decrease in MDA-MB-231 shCon cells but almost no specific effect on SKBR3 shCon cells.

The tested peptides were further tested for their effect on p53 target gene expression in SKBR3 cells expressing endogenous R175H p53. The results are shown in FIG. 16, which shows a bar graph of a representative experiment performed on SKBR3 ShCon cells and SKBR3 Shp53 cells, knocked down for p53 expression. In essence, these cells were plated in 12-well dishes; the indicated peptides were added directly to the medium at a concentration of 5 ug/ml. 18 hours later cells were harvested, followed by qRT-PCR analysis. Expression level of p21, PUMA and Mdm2 was evaluated. Expression of those genes in non-treated cells is considered background and all results were normalized to it, as well as to GAPDH. As seen, some of the lead peptides exhibited a significant transactivation of p53 target genes. This effect was mediated through Mut-p53 since it was not observed in SKBR3 shp53 cells. pCAP-155, pCAP-144 and pCAP-148 showed among the highest transactivation levels.

Effect of Test Peptides on Apoptosis and Correlation to Activation of p53 Target Genes

FIGS. 17A and 17B illustrate a representative experiments performed on ES2 ovarian carcinoma cells (FIGS. 17A-D) expressing Mut-p53 with a mutation at positions 241 within the DBD. Briefly, the cells were plated in 6 cm dishes, and the indicated peptides were added directly to the medium at a concentration of 12 ug/ml at the indicated time points. Cells were harvested, and 60% of the cells were taken for Annexin-PI apoptosis assay and 40% for extraction of RNA, cDNA synthesis and real time PCR analysis. Apoptosis was assayed using the Annexin-V staining kit (Roche, REF 11 988 549 001). Non-fixed cells were stained with both anti Annexin FITC conjugated antibody to detect apoptotic cells, and PI (propidium-iodide) to stain dead cells permeable to the compound, according to the manufacturer's instructions. Stained cells were then analyzed by flow cytometry. A total of 10,000 cells was counted for each sample and divided into four subpopulations according to staining intensity: cells negative for both PI and Annexin (−PI, −Annexin) are termed live; cells negative for PI and positive for Annexin (−PI, +Annexin) are going through early stages of apoptosis; cells positive for PI and Annexin (+PI, +Annexin) are dead cells that underwent an apoptotic process; and cells positive for PI and negative for Annexin (+PI, −Annexin) are assumed to be dead cells that died a non-apoptotic death such as necrosis. As seen in the FIGS. 17A, 17B non-treated cells (time 0 h) are mostly (94%) negative for both PI and Annexin, meaning that the cells are viable and well. Treatment with pCAPs 242 and 250 causes a rapid increase in apoptotic cells followed by cell death and after 5 hours of treatment 12% of cells are Annexin positive and about 7% are dead. After 16 and 24 hours of treatment with pCAP 250 the apoptotic population increases to about 27% and dead cells accumulate to 29% at 16h and 36% after 24h. This trend is true for pCAP 242 as well, although its effects are attenuated and slower. The effect of peptides on cell viability is accompanied by significant transactivation of p53 target genes as seen in FIGS. 17C and 17D, which show the expression of 4 representative targets. As seen all the genes are activated following peptide treatment, and p21 and PUMA mRNA expression increase over time up to 10 fold and 6 fold following treatment with pCAP 250 and pCAP 242, respectively. CD95 and Btg-2 expression is elevated up to 6 fold over non-treated cells.

Example 12: In-Vivo (Preclinical) Testing of Mut-p53 Reactivating Peptides

The in-vivo (preclinical) experiments were performed in two types of models: human xenograft models in nude mice and Mut-p53 “knock-in” mice. In each model, the effects of intratumoral injection of the tested peptides on tumor growth and animal survival are determined.

In the xenograft preclinical model, tumor cells are transfected with a luciferase expression vector, allowing tumor monitoring by live imaging.

In the Mut-p53 “knock-in” mice model a lung specific conditional Mut-p53 knock-in mouse is used (Kim, C. F., et al., Mouse models of human non-small-cell lung cancer: raising the bar. Cold Spring Harb. Symp. Quant. Biol., 2005. 70: p. 241-50. Olive, K. P., et al., Mutant p53 gain of function in two mouse models of Li-Fraumeni syndrome. Cell, 2004. 119(6): p. 847-60). This model offers a compound conditional knock-in mice with mutations in K-ras combined with one of three p53 alleles: R273H, R175H, or a p53-null allele. Infection with AdenoCre induces recombination of the conditional alleles and was shown to produce K-ras-induced lung adenocarcinomas as early as 6 weeks after tumor initiation. This model closely recapitulates several aspects of advanced human pulmonary adenocarcinoma and it allows for two different mutants (175 and 273) to be expressed from the endogenous p53 promoter, at physiological levels, with the correct spatial and temporal profile. This model allows to demonstrate the features of the tested reactivating peptides, in vivo, with respect to several crucial; safety-negligible effect on normal mouse tissue or non-infected mice; efficacy-reduction in tumor size and number in treated mice compared to the control; and specificity to tumor reduction in Mut-p53 expressing mice compared to p53 knock out mice. In addition, dose escalation experiments are performed with positive control peptides, to evaluate the minimal active concentrations and the maximal tolerated dose.

Preclinical Trials in a Xenograft Model

MDA-MB-231 cells endogenously expressing p53 R280K were infected with a luciferase expression vector and either shp53 for p53 knockdown or mouse NOXA shRNA (shmNOXA) as a nonspecific control. MDA-MB-231 cells are highly tumorigenic, forming aggressive, fast growing tumors, as well as being metastatic in humans. In total 10 mice were injected. Each mouse was injected subcutaneously with 2*10⁶ MDA-MB-231 cells expressing shp53 in the right flank, and with 2*10⁶ MDA-MB-231 cells expressing shmNOXA on the left side. Tumors were allowed to grow for 14 days in order to reach visible size. Growth was monitored by live imaging, using the IVIS200 system. In this system, luciferase bioluminescence is proportional to cancer cell number. The results are presented in FIGS. 18A to 18C and FIGS. 19A to 19C. 14 days post injection of the cells, 4 mice (mice 7-10) were assigned to the control group (FIGS. 18A to 18C) and 6 mice (mice 1-6) were assigned to the treatment group (FIGS. 19A to 19C). Control treatment was composed of a mixture of 3 control peptides (pCAPs 76, 77 and 12), which showed no effect (phenotype) on p53 in vitro. The treatment group mice were injected with a mixture of 3 peptides (pCAPs 174, 155 and 159) that showed the best phenotypic effects in vitro on p53. pCAP-159 (SEQ ID NO:312) has a similar sequence to pCAP-60 (SEQ ID NO:302) with the addition of arginine residues, the peptide is composed of D-amino acids and is synthesized in the reverse order (pCAP-159: rrrrrrrrglrgrriflifs (SEQ ID NO:312)) compared to pCAP-60: SFILFIRRGRLG, (SEQ ID NO:302) (lowercase letters stand for D-amino acids), in a “retro-inverso” strategy. Peptides were injected directly into the tumor (intra-tumoral injection) three times a week in a volume of 40p1 per tumor and a concentration of 50 μg/ml for each peptide in the mix. Therefore a total of 6 μg mix of either the control peptides or the treatment peptides was administered each time to each mouse. The mice were monitored for a total of 5 weeks from the start of the peptide treatment. Bioluminescence was measured every 7 days. As shown in FIG. 18A, shmNOXA tumors, expressing endogenous Mut-p53, showed a 6-15 fold (logarithmic scale) increase in luciferase intensity over the time-course of the experiment when treated with the control peptide mix. Mouse 10 had to be sacrificed after 28 days of treatment since the tumors reached a limiting large size. FIG. 19A shows the analysis of mice treated in parallel with a mixture of 3 Mut-p53-activating peptides. As seen in FIG. 19A, none of the tumors showed a significant increase in number of cancer cells over the 35 day period of the experiment. Two of the tumors (mouse-1 and mouse-4) showed a partial response to treatment, evident as a reduction of 50% to 65%, respectively, in bioluminescence. Mice number 2 and 5 showed a complete response, with luciferase readings that were as low or close to background threshold detection levels of the IVIS system (5*10⁶ photons) even after 21 days of treatment. Administration of peptides was discontinued after 35 days, and mice number 2 and 5 were left without any further treatment and monitored for another 21 days. No tumor reappearance was detected in those mice either visually or by live imaging.

Preclinical Trial #2

MDA-MB-231 cells endogenously expressing p53 R280K were infected with a luciferase expression vector 15 mice were injected subcutaneously with 1×10⁶ MDA-MB-231-luc cells on both hips. Tumors were allowed to grow for 10 days in order to reach visible size and from that time point onwards tumor growth was monitored by live imaging. The results are presented in FIGS. 20A to 20C. 18 days post injection of the cells, 6 mice were assigned to the control group and 9 mice were assigned to the treatment group. As before, control treatment involved a mixture of 3 control peptides (pCAPs 76, 77 and 12). The treatment group mice were injected with a mixture of 3 peptides (pCAPs 174, 155 and 159). Peptides were injected directly into the tumor (intra-tumoral injection) three times a week in a volume of 40p1 per tumor and a concentration of 50 μg/ml for each peptide in the mix. As shown in FIGS. 20A-D, both the control and the treatment group showed a similar behavior before treatment; about 2-3 fold (logarithmic scale) increase in luciferase intensity (day 10-18). FIG. 20A shows the analysis of mice treated in parallel with a mixture of 3 control peptides: as seen, the control treatment has only a very mild effect on tumor growth, reducing the rate of growth when compared to the period before treatment. However, as seen in FIG. 20B, treatment with the mixture of three p53 reactivating pCAPs caused a significant decrease in the luminescence of the MDA-MB-231 tumors. After a single injection of pCAP mix, the average luminescence was reduced by 70% and 7 out of the 18 tumors showed total regression with live imaging readings close to the background detection threshold (data not shown). As shown in FIG. 20B, 12 days after beginning of treatment (4 injections) the average tumor luminescence was decreased by 93%, and 11 out of 18 tumors showed a complete response. Only one of the 18 tumors showed either no or a week response. This tumor was relatively big before beginning of treatment, therefore it is possible that the pCAP dose was not sufficient to cause a significant response.

Preclinical Trial #3—SW-480 Colon Carcinoma Cells

After observing the highly significant result in the MDA-MB-231 experiment, additional studies were aimed to extend the observation and examine cells from a different origin, harboring a different p53 point mutation. The SW-480 colon carcinoma cell line harbors two endogenous p53 mutations: the R273H and P309S. SW-480 cells were stably infected with the luciferase reporter gene, and 10⁶ cells were subcutaneously injected into nude mice. The experiment contained 15 mice that were randomly divided during the experiment into 3 groups: a control group treated with a cocktail of 3 pCAPs previously proven ineffective, a group treated with a cocktail of 3 effective pCAP (250, 308, 325) and finally a group treated with a single peptide, the pCAP-325. The duration of the SW-480 experiment was 42 days from the point of cell implantation. The time line is relative to the first day of treatment which is marked as day 0. FIGS. 21A-E show tumor growth over time in all three groups as measured by live imaging in the IVIS. As seen, over time the control tumors show an average increase of 2.75 fold in tumor size (as inferred from the change in the log of luminescence intensity mean from 9.24 at day 0 to 9.68 at day 35, presented in FIG. 21A). The tumors in the mix treatment group show a decrease equivalent to a 96.7% tumor size decrease (as inferred from the change in log of luminescence intensity mean from 9.13 at day 0 to 7.65 at day 35, presented in FIG. 21B). Similarly, the tumors in the pCAP 325 group showed an average fold change of 0.043 which is equivalent to a 95.6% tumor size decrease (as inferred from the changed in log of luminescence intensity mean from 8.97 at day 0 to 7.61 at day 35, presented in FIG. 21C).

Summary of Preclinical Experiments

4 pre-clinical experiments have already been performed thus far, using the xenograft model of Mut-p53 expressing cells transfected with a luciferase expression vector, allowing tumor monitoring by live imaging. Two experiments were performed with MDA-MB-231 triple negative breast cancer cells (p53 R280K), one experiment used SW-480 colon cancer carcinoma cells (p53 R273H) and another experiment used SKBR3 breast cancer cells (p53 R175H). In each experiment, cells from the corresponding cell line were injected subcutaneously and allowed the formation of well-established tumors visible both by eye and by live imaging (typically 2-3 weeks). A treatment regimen was then administered, composed of intra-tumor injection of either effective lead peptides or control peptides (showing no activity in-vitro) every three days for a period of up to 42 days.

In all pre-clinical experiments performed, mice treated with lead peptides have shown a very significant decrease in all of their tumor parameters (percentages vary among different experiments); mean luminescence signal (81%-99% as measured by IVIS), tumor weight and volume (72%-93% measured after tumor extraction). The tumors of mice treated with control peptides on the other hand, continued to grow, although at a reduced rate compared to growth rate before treatment. Almost all of the tumors treated with lead peptides responded to treatment, and 35%-70% of treated tumors showed a complete response with tumors regressing to below threshold detection levels. Six of the mice showing complete response were kept alive for two months after completion of the experiment (without treatment) and no recurrence of tumors was detected.

In-Vivo Testing of Toxicity of Peptides

In total, 6 mice were used to test toxicity of the peptide mix: two mice for each peptide concentration. The peptide mix used in this experiment was the same as that described above (FIGS. 19A to 19C) (pCAPs 174, 155 and 159). Mice were injected intraperitoneally, three times a week for three weeks, with a peptide mix prepared at a concentration of 100 ug/ml. Two mice were injected with a volume of 40p1 resembling the total amount received by mice in the preclinical testing. Two mice were injected with 120p1, and the remaining two mice were injected with 400p1. Given that the average weight of a mouse is 20 g, these amounts represent concentrations of 0.6, 1.8 and 6 mg/Kg, respectively. The mice were inspected daily after injection. No visible change was detected in any of the mice. Furthermore, the tissue surrounding the tumors of mice used in the preclinical experiment (FIGS. 18A to 18C and FIGS. 19A to 19C) was examined after the mice were sacrificed, for signs of necrosis or inflammation. However, the tissue surrounding the tumor appeared normal in all cases, indicating no major toxic effect of the treatment with the pCAP peptides.

Table 10 summarizes the activity of peptides tested in the present invention.

TABLE 1 Gene Forward primer Reverse primer p53 CCCAAGCAATGGATGATTTGA GGCATTCTGGGAGCTTCATCT (SEQ ID NO: 343) (SEQ ID NO: 344) p21 GGCAGACCAGCATGACAGATT GCGGATTAGGGCTTCCTCTT (SEQ ID NO: 345) (SEQ ID NO: 346) PUMA GACCTCAACGCACAGTACGAG AGGAGTCCCATGATGAGATTGT (SEQ ID NO: 347) (SEQ ID NO: 348) MDM2 AGGCAAATGTGCAATACCAAC GGTTACAGCACCATCAGTAGGT A (SEQ ID NO: 349) ACAG (SEQ ID NO: 350) Wig1 CGGCAGAGAATTCCACGTGAT ATCTCTTCGCCAGCTCCAACA (SEQ ID NO: 351) (SEQ ID NO: 352) Noxa GCAGAGCTGGAAGTCGAGTGT AAGTTTCTGCCGGAAGTTCAG (SEQ ID NO: 353) (SEQ ID NO: 354) Fas receptor ACTGTGACCCTTGCACCAAAT GCCACCCCAAGTTAGATCTGG (SEQ ID NO: 355) (SEQ ID NO: 356) BTG2 AGGCACTCACAGAGCACTACA GCCCTTGGACGGCTTTTC (SEQ AAC (SEQ ID NO: 357) ID NO: 358) GAPDH ACCCACTCCTCCACCTTTGA CTGTTGCTGTAGCCAAATTCGT (SEQ ID NO: 359) (SEQ ID NO: 360)

TABLE 2 Selection for R175H p53. Selection round selection marker Titer of phage 1 1620Ab + R175Hp53 100 2 1620Ab + R175Hp53  10⁵ 2 1620Ab 5 * 10⁴ 3 1620Ab + R175Hp53  10⁶ 3 1620Ab 2 * 10⁶

TABLE 3 Alternating selection for Mut-p53 and WT p53. Selection round The selection marker Titer of phage 1 PAb1620 + p53 R175H 2 * 10² 2 His-WT p53 + Ni 2 * 10³ 3 PAb1620 + p53 R175H 10⁵ 3 PAb1620 4 * 10³

TABLE 4 Selection # Library round Selection type Titer 1 phd-7 1° 1620 + 175 2 * 10² 31 phd-12 1° 1620 + 175 2 * 10³ 32 phd-7 1° Tag--wt 1 * 10³ 81 phd-12 1° Tag--wt 5 * 10³ 4 phd-7 1° RE--wt 1 * 10³ 33 phd-7 2° 1620 + 175, 1620-wt 2 * 10⁵ 39 phd-7 2° 1620 + 175, 1620 + 175 1.5 * 10⁴   47 phd-7 2° 1620 + 175, 1620 + 175 2 * 10⁴ 45 phd-7 2° 1620 + 175, 1620-175 2 * 10⁴ 52 phd-12 2° Tag-wt, 1620 + 175 1.5 * 10⁶   41 phd-7 2° 1620 + 175, 1620 8 * 10³ 90 phd-12 2° Tag-wt, 1620 + 175 1.5 * 10⁵   34 phd-7 2° 1620 + 175, Tag-wt 5 * 10⁴ 40 phd-7 2° 1620 + 175, Tag + 175 3 * 10⁴ 48 phd-12 2° 1620 + 175, Tag + 175 4 * 10⁴ 40 phd-7 2° 1620-wt, Tag + 175 4 * 10⁴ 44 phd-12 2° 1620 + 175, Tag 1 * 10³ 51 phd-7 2° 1620-wt, Tag + 175 2 * 10⁶ 83 phd-7 2° Tag-wt, Tag + 175 2 * 10⁶ 55 phd-12 2° 1620 + 175, Tag-wt 2 * 10⁴ 5 phd-7 2° 1620 + 175, Ni-wt 3 * 10⁴ 82 phd-7 2° Tag-wt, Ni-wt 3 * 10³ 10 phd-12 2° 1620 + 175, Ni-wt 1 * 10⁵ 38 phd-7 2° 1620 + 175, RE-wt 5 * 10⁵ 53 phd-12 2° 1620 + 175, RE-wt 5 * 10⁴ 86 phd-7 2° Tag-wt, RE-wt 2 * 10⁵ 91 phd-12 2° Tag-wt, RE-wtDBD 1 * 10⁵ 35 phd-7 3° 1620 + 175, Ni-wt, 1620-wt 3 * 10⁵ 42 phd-12 3° 1620 + 175, Ni-wt, 1620 + 175 5 * 10⁴ 64 phd-7 3° 1620 + 175, RE-wt, 1620 + 175 1 * 10⁶ 36 phd-7 3° 1620 + 175, Ni-wt, Tag-wt 1 * 10⁶ 43 phd-7 3° 1620 + 175, Ni-wt, Tag + 175 2 * 10⁶ 56 phd-12 3° 1620 + 175, Ni-wt, Tag + 175 2 * 10⁵ 65 phd-7 3° 1620 + 175, RE-wt , Tag + 175 2 * 10⁶ 69 phd-7 3° Tag-wt, 1620 + 175, Tag + 175 5 * 10⁶ 85 phd-12 3° 1620 + 175, RE-wt, Tag + 175 2 * 10⁵ 92 phd-7 3° 1620 + 175, Ni-wt, Tag-wtDBD 3 * 10⁵ 93 phd-7 3° 1620 + 175, Ni-wt, Tag + 175 4 * 10⁵ 94 phd-12 3° 1620 + 175, Ni-wt, Tag + 249DBD 4 * 10⁶ 95 phd-7 3° Tag-wt, 1620 + 175, Tag + 175 5 * 10⁶ 98 phd-7 3° 1620-wt, Tag + 175, Tag + 249DBE 5 * 10⁶ 37 phd-7 3° 1620 + 175, Ni-wt, RE-wt 5 * 10⁵ 24 phd-7 3° 1620 + 175, Ni-wt, RE 5 * 10² 57 phd-12 3° 1620 + 175, Ni-wt, RE-wt 8 * 10⁴ 75 phd-7 3° Tag-wt, 1620 + 175, RE-wt 5 * 10⁴ 96 phd-7 3° Tag-wt, 1620 + 175, RE + wtDBD 1.5 * 10⁶   101 phd-7 3° Tag-wt, 1620 + 175, RE 1.5 * 10⁶   97 phd-12 3° 1620 + 175, Tag-wt, RE + wtDBD 5 * 10⁴ 118 phd-12 3° RE + 249DBD 5 * 10⁴

TABLE 5 12 aa Library 7 aa Library #Reads Sequence #Repeats #Reads Sequence #Repeats 553571 KPPDRLWHYTQP 177 194006 HFSHHLK 150 (SEQ ID NO: 322) (SEQ ID NO: 152) 71970 NPNTYVPHWMRQ 66 149576 LPNPPER 111 (SEQ ID NO: 19) (SEQ ID NO: 328) 68333 ATLPFVTDRQGW 85 119076 LHSKTLV 81 (SEQ ID NO: 323) (SEQ ID NO: 329) 60270 FYSHSTSPAPAK 72 96985 H*VHTHQ 54 (SEQ ID NO: 324) (SEQ ID NO: 330) 40419 CYSHSYPTQGHL 43 94834 KLQVPIK 51 (SEQ ID NO: 325) (SEQ ID NO: 182) 20256 SLLIGFGIIRSR 49 93473 KPDSPRV 60 (SEQ ID NO: 165) (SEQ ID NO: 22) 18938 KPPDRLWHYTQP 88385 SSSLGTH 90 (SEQ ID NO: 322) (SEQ ID NO: 331) 13261 SLLIGFGIIRSR 85894 HEVTHHW 66 (SEQ ID NO: 165) (SEQ ID NO: 332) 13048 EFHSFYTARQTG 11 79729 SAPQPAT 81 (SEQ ID NO: 326) (SEQ ID NO: 333) 10943 NHPWQFPNRWTV 7 76099 TPPLTLI 69 (SEQ ID NO: 287) (SEQ ID NO: 334) 10914 SLLIGFGIIRSR 73014 TIHPSIS 42 (SEQ ID NO: 165) (SEQ ID NO: 258) 8643 GAMHLPWHMGTL 8 68925 HPWTHH 48 (SEQ ID NO: 285) (SEQ ID NO: 335) 8622 IPMNFTSHSLRQ 6 51964 SAASDLR 40 (SEQ ID NO: 248) (SEQ ID NO: 336) 7072 KPPDRLWHYTQP 43941 SPLQSLK 33 (SEQ ID NO: 322) (SEQ ID NO: 337) 6657 SDGFVPHFKRQH 4 39254 RPTQVLH 27 (SEQ ID NO: 327) (SEQ ID NO: 338) 6427 SLLIGFGIIRSR 39167 DSLHSTY 24 (SEQ ID NO: 165) (SEQ ID NO: 101) 5311 SEFPRSWDMETN 4 36985 WTLSNYL 30 (SEQ ID NO: 24) (SEQ ID NO: 100)

TABLE 6 SEQ ID pCAP NO: NO: Sequence 17 8 LTFEHYWAQLTS 18 12 GGGGGGGGGGGG 19 19 NPNTYVPHWMRQ 20 25 YRRLLIGMMW 21 26 DEFHSFYTARQTG 22 29 KPDSPRV 23 31 PPYSQFLQWYLS 24 40 SEFPRSWDMETN 25 45 HDTHNAHVG 26 50 WSEYDIPTPQIPP 27 69 SILTLSRRRRRRRRRR 28 73 SCRCRLRGDRGDR 29 76 GGGGGGGGGRRRRRRR 30 77 SEYLCSSLDAAG 31 78 GESFVQHVFRQN 32 79 SVHHHHRMHLVA 33 84 GRRRFCM 34 85 KLTIHHH 35 86 FGSHHEL 36 96 GTVDHHA 37 107 DRLSVFLFIM 38 114 AISHHTR 39 116 KHHPFDHRLGNQ 40 119 HSAHHTM 41 125 ELGLHRH 42 126 RRLRICV 43 156 VPHIHEFTRRRRRRRR 44 164 PLTLI 45 165 SLLIG 46 166 KPPER 47 168 CRIIR 48 169 SFILI 49 171 PHHHS 50 172 EFHS 51 173 RLRRL 52 175 DSPR 53 176 HPWTH 54 177 HFSHH 55 178 RRVI 56 179 ILVI 57 207 RRSRSNEDVEDKTEDE 58 208 RRIRSGGKDHAWTPLHE NH 59 209 HTPHPPVARTSPLQTPRR 60 211 PDSEPPRMELRRR 61 215 RRDTFDIRILMAF 62 218 RREVTELHHTHEDRR 63 223 SPWTHERRCRQR 64 232 RSRSSHLRDHERTHT 65 236 RRRSTNTFLGEDFDQ 66 241 LIGLSTSPRPRIIR 67 248 EIYGESGKTDEHALDTEY RR 68 252 RRVILRSYDGGHSTPHPD 69 253 TGKTFVKRHLTEFEKKY R 70 254 NHFDYDTIELDTAGEYSR RR 71 255 DPEPPRYLPPPPERR 72 260 RRTFIRHRIDSTEVIYQDE D 73 262 ESKTGHKSEEQRLRRYR 74 263 YDDEHNHHPHHSTHRRR 75 264 RRRREVHTIHQHGIVHSD 76 269 DEPLPPPERRR 77 270 SPHPPY 78 271 SPHPPYSPHPPYSPHPPYP 79 272 RRPHNLHHD 80 274 LRDPHPPERRIR 81 283 RRPADQISYLHPPER 82 291 DLQYDFPRIRR 83 292 YDELYQKEDPHRRR 84 294 FKPERFPQNDRRR 85 296 RPADRIRR 86 297 HDFDPRYRDRR 87 300 RIRRDPDSPLPHPE 88 304 myr-RRIRILMFLIGCGRV 89 309 HPHVILPRIRIRIR 90 311 EIHTIHLLPERR 91 320 EPSHPRSRYPRTF 92 321 RNIIIRDFIHFSHIDR 93 322 RRIRDPQIK- myrLEIHFSHID 94 323 myr-DLHTIHIPRDRR 95 324 SHDFPHREPRPERR 96 219 SYRHYSDHWEDRRR 97 2 VWVHDSCHANLQNYRN YLLP 98 4 EHDFEVRGDVVNGRNHQ GPK 99 5 LEVIYMI 100 38 WTLSNYL 101 39 DSLHSTY 102 41 WHHRQQIPRPLE 103 64 APSIFTPHAWRQ 104 66 THFSHHLKGGGRRQRRR P 105 67 LHSKTLVLGGGRRRRGD R 106 71 WTLSNYLGGRKKRRQRR RR 107 81 VRCIFRGIWVRL 108 98 HSSGHNFVLVRQ 109 110 LFILVFR 110 112 TTSHHPK 111 124 VMVLFRILRGSM 112 162 SILT 113 214 RRRESEQRSISLHHHST 114 216 myr- HFNHYTFESTCRRRRC 115 217 HSTPHPPQPPERRR 116 224 RRKSEPHSLSGGYQTGA D 117 234 HRTGHYTRCRQRCRSRS HNRH 118 243 RRCRSILPLLLLSR 119 256 RTLHGRRVILHEGGHSIS DLK 120 266 HHRLSYFIVRRHSTHASR 121 293 RRIRIDPQHD 122 299 ILQPDFLIRPE 123 307 HDPRIIRIR 124 52 SPYPIRT 125 53 ILVIIQRIM 126 101 IRFILIR 127 102 SSVHHRG 128 103 LRRQLQL 129 113 HTTAHTH 130 115 HPHNHTVHNVVY 131 117 DHSKFVPLFVRQ 132 120 SIRTLGRFLIIRV 133 123 GLCRIIL 134 127 SPPIRHH 135 201 HPTHPIRLRDNLTR 136 212 myr-REEETILIIRRR 137 225 HTIHSISDFPEPPDRRRR 138 228 DEDAAHSTGHPHNSQHR RRR 139 240 TEQHHYIPHRRR 140 251 RLRRVILRSYHE 141 265 EEPDRQPSGKRGGRKRR SR 142 273 RDFHTIHPSISRR 143 276 RRVDIHDGQRR 144 277 DQPYPHRRIR 145 281 myr-RDFILFIRRLGRR 146 295 LDLYHPRERR 147 298 RRIRDPLGNEHE 148 303 IVEFRIRR 149 312 RRPRIPDYIL 150 314 RSTPHIHEFIRR 151 319 SHDFYPHWMRERIR 152 13 HFSHHLK 153 32 TSPLQSLK 154 51 AILTLILRRVIWP 155 94 LRFIDYP 156 109 GPIKHHLQHH 157 163 LTLS 158 222 RYEENNGVNPPVQVFES RTR 159 239 REGFYGPWHEQRRR 160 285 RRDIIRHNAHS 161 286 HDFHDYLERR 162 305 IREFDPRRIR 163 310 RLRCLLLLIGRVGRR 164 6 LGIDEDEETETAPE 165 22 SLLIGFGIIRSR 166 27 VHEVTHHWL 167 56 ATPFHQT 168 58 SILPLFLIRRSG 169 72 SCRCRLRRRRRRRRRR 170 105 SRIVLGW 171 111 SNIHHQV 172 121 LTLMRLRIIG 173 122 HSYSPYYTFRQH 174 167 FILIR 175 205 RCRNRKKEKTECLQKESEK 176 213 RRIKMIRTSESFIQHIVS 177 244 RRVSELQRNKHGRKHEL 178 246 RRRLDDEDVQTPTPSEYQN 179 261 RRRQPLPSAPENEE 180 7 SPLQTPAAPGAAAGPALSPV 181 18 SHQVHTHHNN 182 37 KLQVPIK 183 74 IRGRIIRRKKRRQRRRRGDR 184 82 QIPHRSSTALQL 185 88 SYQTMQP 186 140 TDSHSHHRRRRRRRRRRR 187 143 IPMNFTSHSLRQRRRRRRRRR 188 153 YWSAPQPATRRRRRRRRRRR 189 220 STTHPHPGTSAPEPATRRR 190 226 DDSDNRIIRYRR 191 238 TSPHPSLPRHIYPRR 192 247 RRITEIRGRTGKTTLTYIED 193 249 myr-DERTGKTRRYIDTRDIRR 194 275 myr-MTYSDMPRRIITDEDRRR 195 278 RRYDTVIDDIEYRR 196 279 RDTIERPEIRR 197 280 myr-RYRRLILEIWRR 198 284 myr-RHDTHNAHIRR 199 288 THDFDRLLRIRRR 200 289 RHNHIRPDNQ 201 290 RYKEPRITPRE 202 302 LRIEPIRIR 203 306 myr-RLIRIRILM 204 318 RPEFHSFHPIYERR 205 91 STTHIHA 206 92 FPHLVSSLTT 207 99 GLHLFTTDRQGW 208 132 NHPWQFPNRWTRRRRRR 209 145 HSSHHHPVHSWNRRRRRRR 210 316 myr-DIHTIHLPDTHRR 211 10 VAEFAQSIQSRIVEWKERLD 212 49 TRILCIVMM 213 55 FLLPEPDENTRW 214 57 LMSNAQY 215 89 SILTLSCRCRLRLWR 216 95 HQIHRNHTY 217 106 LIRRCSLQR 218 137 GAMHLPWHMGTRRRRRR 219 202 DEDAKFRIRILMRR 220 245 NHITNGGEEDSDCSSRRRRL 221 257 myr-HSSHHHPTVQHRR 222 287 RDFERTIVDI 223 313 myr-RRREILHPEFRILYE 224 14 HHFSHHWKT 225 59 FLIRRSG 226 63 HNHHHSQHTPQH 227 80 HLHKHHYKDSRM 228 231 HRTQSTLILFIRRGRET 229 315 LHFSHIDRR 230 62 YELPHHAYPA 231 133 SLLIGFGIIRSRRRRRRRR 232 135 HTDSHPHHHHPHRRRRR 233 147 ATQHHYIKRRRRRRRRRRR 234 129 FRSFAIPLVVPFRRRRRRR 235 138 YPTQGHLRRRRRRRRRRRR 236 146 HANLHHTRRRRRRRRRRR 237 152 YRRLLIGMRRRRRRRRRRRR 238 233 SHYHTPQNPPSTRRR 239 235 RSYSKLLCLLERLRISP 240 3 FWTQSIKERKMLNEHDFEVR 241 15 THFSHHLKH 242 90 SCRCRLR 243 139 MHPPDWYHHTPKRRRRRR 244 237 HTIHVHYPGNRQPNPPLILQR 245 268 TPSYGHTPSHHRRR 246 301 myr-IRGRIRIIRRIR 247 20 HHPWTHHQRWS 248 48 IPMNFTSHSLRQ 249 118 SNHHHRHHTNTH 250 130 EVTFRHSVVRRRRRRRRRRR 251 149 FPGHTIHRRRRRRRRRRR 252 34 SILTLSRIVLGWW 253 47 TLYLPHWHRH 254 136 SILTLRLRRLRRRRRRRR 255 142 TLYLPHWHRHRRRRRRRRRR 256 43 TDSHSHH 257 11 EWKERLDKEFSLSVYQKMKF 258 30 TIHPSIS 259 33 SILTLRLRRLRR 260 44 VPHIHEFT 261 9 TIIHREDEDEIEW 262 61 KDLPFYSHLSRQ 263 65 THFSHHLKHRRRRRRRRRR 264 93 ATQHHYIK 265 108 IIRGNFLIGGRL 266 131 LPNPPERHHRRRRRRRRRRR 267 158 SFILFIRRGRLGRGDR 268 100 FPGHTIH 269 128 CILRLWW 270 206 RRRSHSQENVDQDTDE 271 204 MSTESNMPRLIQNDDRRR 272 104 LLRLGLI 273 23 IRILMFLIGCGR 274 17 LHSKTLVL 275 24 LRCLLLLIGRVG 276 258 FLIGPDRLIRSR 277 16 LPNPPERHH 278 28 HTDSHPHHHHPH 279 160 Fitc- SFILFIRRGRLGRRRRRRRRR 280 83 HSSHHHPVHSWN 281 259 myr-RTLIGIIRSHHLTLIRR 282 54 IRGRIIR 283 150 IIRGNFLIGGRLRRRRRRRRR 284 170 IRILM 285 35 GAMHLPWHMGTL 286 267 KRGGRKRRGGGHRLSYFIRR 287 21 NHPWQFPNRWTV 288 42 MHPPDWYHHTPKH 289 141 SWQALALYAAGWRRRRRR 290 161 HNAH 291 210 DEFERYRRFSTSRRR 292 1 EVTFRHSVV 293 75 TRILCIVRKKRRQRRRRGDR 294 70 SILTLSRGRKKRRQRRRR 295 151 CILRLWWRRRRRRRRRRR 296 46 ASWQALALYAAGW 297 229 myr-PRVLPSPHTIHPSQYP 298 87 HANLHHT 299 157 SFILFIRRGRLGRKKRRQRRRP 300 36 YPTQGHLR 301 68 YRRLLIGMMWRRRRRRRRRR R 302 60 SFILFIRRGRLG 303 134 IRILMFLIGCGRRRRRRRR 304 308 myr-RRICRFIRICRVR 305 155 IRGRIIRRRRRRRRRR 306 203 RRRHDSCHNQLQNYDHSTE 307 148 WNHHHSTPHPRRRRRRRRRR 308 282 myr-RRPVAPDLRHTIHIPPER 309 317 RRDIHTIHPFYQ 310 97 WNHHHSTPHPAH 311 144 SFILFIRRGRLGRRRRRRRRR 312 159 rrrrrrrrglrgrriflifs 313 326 myr-RRHNAHHSTPHPDDR 314 174 HSTPHP 315 154 LRCLLLLIGRVGRKKRRQRR 316 221 myr-RRKHNKHRPEPDSDER 317 325 myr-RRIRDPRILLLHFD 318 230 RKRGKSYAFFVPPSESKERW 319 227 myr-RRKILFIRLMHNKH 320 242 myr-RRLIVRILKLPNPPER 321 250 myr-RRHSTPHPD

TABLE 7 SEQID NJ: Name Peptide Seq Conform DNA Viability Luc PCR AS* 292 pCAP1 EVTFRHSVV 2 2 3 3 4 3 3 2 3 5 3 32 97 pCAP2 VWVHDSCHANLQNYRNYLLP 2 2 240 pCAP3 FWTQSIKERKMLNEHDFEVR 2 3 3 2 2 12 98 pCAP4 EHDFEVRGDVVNGRNHQGPK 2 2 99 pCAP5 LEVIYMI 2 2 164 pCAP6 LGIDEDEETETAPE 2 3 5 180 pCAP7 SPLQTPAAPGAAAGPALSPV 3 3 6 17 pCAP8 LTFEHYWAQLTS 0 261 pCAP9 TIIHREDEDEIEW 2 3 3 2 2 3 2 17 211 pCAP10 VAEFAQSIQSRIVEWKERLD 3 3 2 8 257 pCAP11 EWKERLDKEFSLSVYQKMKF 3 3 3 5 2 16 18 pCAP12 GGGGGGGGGGGG 0 152 pCAP13 HFSHHLK 1 3 4 224 pCAP14 HHFSHHWKT 2 2 2 3 9 241 pCAP15 THFSHHLKH 2 2 2 3 3 12 277 pCAP16 LPNPPERHH 2 3 3 3 3 4 4 2 24 274 pCAP17 LHSKTLVL 2 2 3 3 3 3 4 3 23 181 pCAP18 SHQVHTHHNN 3 3 6 19 pCAP19 NPNTYVPHWMRQ 0 247 pCAP20 HHPWTHHQRWS 2 3 3 2 3 13 287 pCAP21 NHPWQFPNRWTV 4 2 2 2 2 3 3 4 3 4 29 165 pCAP22 SLLIGFGIIRSR 3 2 5 273 pCAP23 IRILMFLIGCGR 1 1 3 3 3 3 4 3 1 22 275 pCAP24 LRCLLLLIGRVG 3 2 2 3 3 3 3 4 23 20 pCAP25 YRRLLIGMMW 0 21 pCAP26 DEFHSFYTARQTG 0 166 pCAP27 VHEVTHHWL 2 3 5 278 pCAP28 HTDSHPHHHHPH 2 2 3 3 3 4 1 3 3 24 22 pCAP29 KPDSPRV 0 258 pCAP30 TIHPSIS 3 2 3 2 2 2 2 16 23 pCAP31 PPYSQFLQWYLS 0 153 pCAP32 TSPLQSLK 1 3 4 259 pCAP33 SILTLRLRRLRR 2 2 4 4 4 16 252 pCAP34 SILTLSRIVLGWW 2 4 4 4 14 285 pCAP35 GAMHLPWHMGTL 2 2 2 4 3 2 3 3 3 4 3 28 300 pCAP36 YPTQGHLR 6 3 2 2 3 3 3 5 3 3 3 3 39 182 pCAP37 KLQVPIK 2 2 2 6 100 pCAP38 WTLSNYL 2 2 101 pCAP39 DSLHSTY 2 2 24 pCAP40 SEFPRSWDMETN 0 102 pCAP41 WHHRQQIPRPLE 2 2 288 pCAP42 MHPPDWYHHTPKH 3 2 4 2 2 3 3 3 3 4 29 256 pCAP43 TDSHSHH 2 3 3 3 4 15 260 pCAP44 VPHIHEFT 2 3 3 3 2 3 16 25 pCAP45 HDTHNAHVG 0 296 pCAP46 ASWQALALYAAGW 2 2 2 2 3 3 4 6 2 3 3 2 34 253 pCAP47 TLYLPHWHRH 2 3 3 3 3 14 248 pCAP48 IPMNFTSHSLRQ 2 2 3 3 3 13 212 pCAP49 TRILCIVMM 5 3 8 26 pCAP50 WSEYDIPTPQIPP 0 154 pCAP51 AILTLILRRVIWP 2 2 4 124 pCAP52 SPYPIRT 3 3 125 pCAP53 ILVIIQRIM 3 3 282 pCAP54 IRGRIIR 3 2 2 4 4 4 4 3 26 213 pCAP55 FLLPEPDENTRW 4 4 8 167 pCAP56 ATPFHQT 3 2 5 214 pCAP57 LMSNAQY 2 2 4 8 168 pCAP58 SILPLFLIRRSG 2 3 5 225 pCAP59 FLIRRSG 2 2 3 2 9 302 pCAP60 SFILFIRRGRLG 2 3 3 3 4 2 3 5 4 3 4 4 40 262 pCAP61 KDLPFYSHLSRQ 2 3 2 2 5 3 17 230 pCAP62 YELPHHAYPA 5 2 3 10 226 pCAP63 HNHHHSQHTFQH 2 3 2 2 9 103 pCAP64 APSIFTPHAWRQ 2 2 263 pCAP65 THFSHHLKHRRRRRRRRRR 2 2 2 2 2 4 3 17 104 pCAP66 THFSHHLKGGGRRQRRRP 2 2 105 pCAP67 LHSKTLVLGGGRRRRGDR 2 2 301 pCAP68 YRRLLIGMMWRRRRRRRRRRR 4 5 4 3 5 5 4 2 2 2 3 39 27 pCAP69 SILTLSRRRRRRRRRR 0 294 pCAP70 SILTLSRGRKKRRQRRRR 3 3 2 2 3 3 3 3 5 4 2 33 106 pCAP71 WILSNYLGGRKKRRORRRR 2 2 169 pCAP72 SCRCRLRRRRRRRRRR 2 3 5 28 pCAP73 SCRCRLRGDRGDR 0 183 pCAP74 IRGRIIRRKKRRQRRRRGDR 3 3 6 293 pCAP75 TRILCIVRKKRRQRRRRGDR 3 3 2 2 5 5 3 4 2 3 32 29 pCAP76 GGGGGGGGGRRRRRRR 0 30 pCAP77 SEYLCSSLDAAG 0 31 pCAP78 GESFVQHVFRQN 0 32 pCAP79 SVHHHHRMHLVA 0 227 pCAP80 HLHKHHYKDSRM 3 3 3 9 107 pCAP81 VRCIFRGIWVRL 2 2 184 pCAP82 QIPHRSSTALQL 3 3 6 280 pCAP83 HSSHHHPVHSWN 4 1 5 4 4 3 3 1 25 33 pCAP84 GRRRFCM 0 34 pCAP85 KLTIHHH 0 35 pCAP86 FGSHHEL 0 298 pCAP87 HANLHHT 3 2 2 3 3 4 4 3 5 4 4 37 185 pCAP88 SYQTMQP 2 4 6 215 pCAP89 SILTLSCRCRLRLWR 2 4 2 8 242 pCAP90 SCRCRLR 2 4 4 2 12 205 pCAP91 STTHIHA 4 3 7 206 pCAP92 FPHLVSSLTT 4 3 7 264 pCAP93 ATQHHYIK 4 4 2 3 4 17 155 pCAP94 LRFIDYP 4 4 216 pCAP95 HQIHRNHTY 4 4 8 36 pCAP96 GTVDHHA 0 310 pCAP97 WNHHHSTPHPAH 3 3 6 4 4 5 4 4 4 2 3 5 47 108 pCAP98 HSSGHNFVLVRQ 2 2 207 pCAP99 GLHLFTTDRQGW 2 3 2 7 268 pCAP100 FPGHTIH 5 3 3 2 3 3 19 126 pCAP101 IRFILIR 3 3 127 pCAP102 SSVHHRG 3 3 128 pCAP103 LRRQLQL 3 3 272 pCAP104 LLRLGLI 3 3 6 3 3 3 21 170 pCAP105 SRIVLGW 3 2 5 217 pCAP106 LIRRCSLQR 3 5 8 37 pCAP107 DRLSVFLFIM 0 265 pCAP108 IIRGNFLIGGRL 3 3 2 3 3 3 17 156 pCAP109 GPIKHHLQHH 2 2 4 109 pCAP110 LFILVFR 2 2 171 pCAP111 SNIHHQV 3 2 5 110 pCAP112 TTSHHPK 2 2 129 pCAP113 HTTAHTH 3 3 38 pCAP114 AISHHTR 0 130 pCAP115 HPHNHTVHNVVY 3 3 39 pCAP116 KHHPFDHRLGNQ 0 131 pCAP117 DHSKFVPLFVRQ 3 3 249 pCAP118 SNHHHRHHTNTH 2 2 3 3 3 13 40 pCAP119 HSAHHTM 0 132 pCAP120 SIRTLGRFLIIRV 3 3 172 pCAP121 LTLMRLRIIG 2 3 5 173 pCAP122 HSYSPYYTFRQH 2 3 5 133 pCAP123 GLCRIIL 3 3 111 pCAP124 VMVLFRILRGSM 2 2 41 pCAP125 ELGLHRH 0 42 pCAP126 RRLRICV 0 134 pCAP127 SPPIRHH 3 3 269 pCAP128 CILRLWW 3 2 3 3 3 3 2 19 234 pCAP129 FRSFAIPVVPFRRRRRRR 4 3 2 2 11 250 pCAP130 EVTFRHSVVRRRRRRRRRRR 6 3 4 13 266 pCAP131 LPNPPERHHRRRRRRRRRRR 3 3 3 3 2 3 1 18 208 pCAP132 NHPWQFPNRWTRRRRRR 3 4 7 231 pCAP133 SLLIGFGIIRSRRRRRRRR 2 2 6 10 303 pCAP134 IRILMFLIGCGRRRRRRRR 4 4 3 2 6 6 3 3 3 3 3 40 232 pCAP135 HTDSHPHHHHPHRRRRR 3 3 2 2 10 254 pCAP136 SILTLRLRRLRRRRRRRR 3 3 5 3 14 218 pCAP137 GAMHLPWHMGTRRRRRR 3 3 2 8 235 pCAP138 YPTQGHLRRRRRRRRRRRR 3 4 2 2 11 243 pCAP139 MHPPDWYHHTPKRRRRRR 2 3 2 2 3 12 186 pCAP140 TDSHSHHRRRRRRRRRRR 3 3 6 289 pCAP141 SWQALALYAAGWRRRRRR 6 3 5 3 3 3 3 3 29 255 pCAP142 TLYLPHWHRHRRRRRRRRRR 6 2 3 3 14 187 pCAP143 IPMNFTSHSLRQRRRRRRRRR 2 4 6 311 pCAP144 SFILFIRRGRLGRRRRRRRRR 2 2 2 2 3 3 3 3 3 2 6 6 4 4 4 49 209 pCAP145 HSSHHHPVHSWNRRRRRRR 3 2 2 7 236 pCAP146 HANLHHTRRRRRRRRRRR 3 2 3 3 11 233 pCAP147 ATQHHYIKRRRRRRRRRRR 4 3 3 10 307 pCAP148 WNHHHSTPHPRRRRRRRRRR 4 4 4 5 3 4 2 3 3 3 4 4 43 251 pCAP149 FPGHTIHRRRRRRRRRRR 3 5 3 2 13 283 pCAP150 IIRGNFLIGGRLRRRRRRRRR 4 4 4 4 3 2 5 26 295 pCAP151 CILRLWWRRRRRRRRRRR 5 4 5 4 3 3 3 3 3 33 237 pCAP152 YRRLLIGMRRRRRRRRRRRR 5 3 3 11 188 pCAP153 YWSAPQPATRRRRRRRRRRR 3 3 6 315 pCAP154 LRCLLLLIGRVGRKKRRORR 6 4 5 4 5 5 5 5 3 4 5 3 57 305 pCAP155 IRGRIIRRRRRRRRRR 3 2 2 5 5 5 4 4 4 4 3 41 43 pCAP156 VPHIHEFTRRRRRRRR 0 299 pCAP157 SFILFIRRGRLGRKKRRQRRRP 1 1 1 2 3 3 3 3 5 2 2 5 2 4 37 267 pCAP158 SFILFIRRGRLGRGDR 1 1 4 4 4 2 2 18 312 pCAP159 rrrrrrrrglrgrriflifs 3 1 1 1 3 5 4 4 5 4 5 4 5 4 4 53 279 pCAP160 Fitc-SFILFIRRGRLGRRRRRRRRR 1 1 4 4 4 4 3 3 24 290 pCAP161 HNAH 3 2 2 2 3 5 3 5 4 29 112 pCAP162 SILT 2 2 157 pCAP163 LTLS 4 4 44 pCAP164 PLTLI 0 45 pCAP165 SLLIG 0 46 pCAP166 KPPER 0 174 pCAP167 FILIR 5 5 47 pCAP168 CRIIR 0 48 pCAP169 SFILI 0 284 pCAP170 IRILM 5 5 5 3 3 3 3 27 49 pCAP171 PHHHS 0 50 pCAP172 EFHS 0 51 pCAP173 RLRRL 0 314 pCAP174 HSTPHP 1 4 4 5 4 5 4 5 4 4 5 1 4 4 54 52 pCAP175 DSPR 0 53 pCAP176 HPWTH 0 54 pCAP177 HFSHH 0 55 pCAP178 RRVI 0 56 pCAP179 ILVI 0 *AS - Activity Score.

TABLE 8 SEQ ID NJ: Name Sequence Similarity Conformation DNA binding Viability PCR AS* 135 pCAP201 HPTHPIRLRDNLTR 14-3-3 3 3 219 pCAP202 DEDAKFRIRILMRR APAF1 3 2 3 8 306 pCAP203 RRRHDSCHNQLQNYDHSTE ASPP1 3 3 2 4 6 4 6 6 4 4 42 271 pCAP204 MSTESNMPRLIQNDDRRR ASPP2 2 4 4 5 5 20 175 pCAP205 RCRNRKKEKTECLQKESEK ATF3 2 3 5 270 pCAP206 RRRSHSQ ENVDQDTDE BAK 2 3 3 2 1 2 6 19 57 pCAP207 RRSRSNEDVEDKTEDE BAK 0 58 pCAP208 RRIRSGGKDHAWTPLHENH BARD1 0 59 pCAP209 HTPHPPVARTSPLQTPRR BCL2 0 291 pCAP210 DEFERYRRFSTSRRR BCL-XL 3 2 2 2 2 6 3 3 6 29 60 pCAP211 PDSEPPRMELRRR BCR 0 136 pCAP212 my r-REEETILIIRRR BRG1 3 3 176 pCAP213 RRIKMIRTSESFIQHIVS BTF 2 3 5 113 pCAP214 RRRESEQRSISLHHHST C-ABL 2 2 61 pCAP215 RRDTFDIRILMAF CARM1 0 114 pCAP216 my r-HFNHYTFESTCRRRRC CAS 2 2 115 pCAP217 HSTPHPPQPPERRR CCDC8 2 2 62 pCAP218 RREVTELHHTHEDRR CEP72 0 96 pCAP219 SYRHYSDHWEDRRR CETD2 1 1 189 pCAP220 STTHPHPGTSAPEPATRRR CHD6 2 2 2 6 316 pCAP221 myr-RRKHNKHRPEPDSDER CTF2 3 5 3 4 4 2 5 6 5 2 5 4 6 6 60 158 pCAP222 RYEENNGVNPPVQVFESRTR CUL7 4 4 63 pCAP223 SPWTHERRCRQR CYP27B1 0 116 pCAP224 RRKSEPHSLSGGYQTGAD DIABLO 2 2 137 pCAP225 HTIHSISDFPEPPDRRRR DMP1 3 3 190 pCAP226 DDSDNRIIRYRR G3BP2 3 3 6 319 pCAP227 my r-RRKILFI RLMHNKH GAS2 4 6 5 5 5 5 6 5 6 3 5 5 3 4 67 138 pCAP228 DEDAAHSTGHPHNSQHRRRR HIPK1 3 3 297 pCAP229 my r-PRVLPSPHTIHPSQYP HIPK2 2 4 4 4 3 3 4 4 4 4 36 318 pCAP230 RKRGKSYAFFVPPSESKERW HMGB1 3 5 5 3 4 3 6 5 5 2 6 4 6 6 63 228 pCAP231 HRTQSTLILFIRRGRET HTRA2 3 6 9 64 pCAP232 RSRSSHLRDHERTHT HZF 0 238 pCAP233 SHYHTPQNPPSTRRR IFI16 3 3 3 2 11 117 pCAP234 HRTGHYTRCRQRCRSRSHNRH KLF4 2 2 239 pCAP235 RSYSKLLCLLERLRISP MIF 2 5 2 2 11 65 pCAP236 RRRSTNTFLGEDFDQ MORTALIN 0 244 pCAP237 HTIHVHYPGN FQPNPPLILQR MULE 3 2 5 2 12 191 pCAP238 TSPHPSLPRHIYPRR NFAT 2 4 6 159 pCAP239 REGFYGPWHEQRRR OGA 2 2 4 139 pCAP240 TEQHHYIPHRRR OSGIN2 3 3 66 pCAP241 LIGLSTSPRPRIIR PAR3 0 320 pCAP242 my r-RRLIVRILKLPNPPER PARC 4 3 6 6 6 6 6 3 4 6 6 5 6 67 118 pCAP243 RRCRSILPLLLLSR PERP 2 2 177 pCAP244 RRVSELQRNKHGRKHEL PIAS1 3 2 5 220 pCAP245 NHITNGGEEDSDCSSRRRRL PIN1 3 3 2 8 178 pCAP246 RRRLDDEDVQTPTPSEYQN PIRH2 3 2 5 192 pCAP247 RRITEIRGRTGKTTLTYIED RAD51 3 3 6 67 pCAP248 EIYGESGKTDEHALDTEYRR RAD51 0 193 pCAP249 my r-DERTGKTRRYIDTRDIRR RAD51 3 3 6 321 pCAP260 my r-RRHSTPHPD RAD9 4 6 5 4 5 5 5 5 6 3 6 6 6 6 72 140 pCAP25I RLRRVILRSYHE RAD9 3 3 68 pCAP252 RRVILRSYDGGHSTPHPD RAD9 0 69 pCAP253 TGKTFVKRHLTEFEKKYR RAN 0 70 pCAP254 NHFDYDTIELDTAGEYSRRR RAS 0 71 pCAP255 DPEPPRYLPPPPERR RASSF5 0 119 pCAP256 RTLHGRRVILHEGGHSISDLK RPA70 2 2 221 pCAP257 my r-HSSHHHPTVQHRR SIN3A 4 4 8 276 pCAP258 FLIGPDRLIRSR SIVA 6 4 5 2 2 4 23 281 pCAP259 myr-RTLIGIIRSHHLTLIRR SMG1 4 5 4 5 3 2 2 25 72 pCAP260 RRTFIRHRIDSTEVIYQDED STK11 0 179 pCAP261 RRRQPLPSAPENEE STK15 2 3 5 73 pCAP262 ESKTGHKSEEQRLRRYR TBP 0 74 pCAP263 YDDEHNHHPHHSTHRRR TSC22 0 75 pCAP264 RRRREVHTIHQHGIVHSD TTK 0 141 pCAP265 EEPDRQPSGKRGGRKRRSR TWIST 3 3 120 pCAP266 HHRLSYFIVRRHSTHASR TWIST 2 2 286 pCAP267 KRGGRKRRGGGHRLSYFIRR TWIST 3 2 4 6 2 3 2 2 2 2 28 245 pCAP268 TPSYGHTPSHHRRR WT1 3 5 4 12 76 pCAP269 DEPLPPPERRR 0 77 pCAP270 SPHPPY 0 78 pCAP271 SPHPPYSPHPPYSPHPPYP 0 79 pCAP272 RRPHNLHHD 0 142 pCAP273 RDFHTIHPSISRR 3 3 80 pCAP274 LRDPHPPERRIR 0 194 pCAP275 my r-MTYSDMPRRIITDEDRRR ASPP2 3 3 6 143 pCAP276 RRVDIHDGQRR 3 3 144 pCAP277 DQPYPHRRIR 3 3 195 pCAP278 RRYDTVIDDIEYRR 3 3 6 196 pCAP279 RDTIERPEIRR 3 3 6 197 pCAP280 myr-RYRRLILEIWRR 3 3 6 145 pCAP281 myr-RDFI LFIRRLGRR 3 3 308 pCAP282 myr-RRPVAPDLRHTIHIPPER LTA 4 3 3 4 4 6 2 2 4 4 4 3 43 81 pCAP283 RRPADQISYLHPPER 0 198 pCAP284 myr-RHDTHNAHIRR 6 6 160 pCAP285 RRDIRHNAHS 4 4 161 pCAP286 HDFHDYLERR 4 4 222 pCAP287 RDFERTIVDI 4 4 8 199 pCAP288 THDFDRLLRIRRR 2 4 6 200 pCAP289 RHNHIRPDNQ 2 4 6 201 pCAP290 RYKEPRITPRE 4 2 6 82 pCAP291 DLQYDFPRIRR 0 83 pCAP292 YDELYQKEDPHRRR 0 121 pCAP293 RRIRIDPQHD 2 2 84 pCAP294 FKPERFPQNDRRR 0 146 pCAP295 LDLYHPRERR 3 3 85 pCAP296 RPADRIRR 0 86 pCAP297 HDFDPRYRDRR 0 147 pCAP298 RRIRDPLGNEHE 3 3 122 pCAP299 ILQPDFLIRPE 2 2 87 pCAP300 RIRRDPDSPLPHPE 0 246 pCAP301 myr-IRGRIRIIRRIR 3 3 6 12 202 pCAP302 LRIEPIRIR 3 3 6 148 pCAP303 IVEFRIRR 3 3 88 pCAP304 my r-RRIRILMFUGCGRV 0 162 pCAP305 IREFDPRRIR 4 4 203 pCAP306 my r-RLIRIRILM 6 6 123 pCAP307 HDPRIIRIR 2 2 304 pCAP308 my r-RRICRFIRICRVR CDC25B 6 4 4 6 4 4 2 4 6 40 89 pCAP309 HPHVILPRIRIRIR 0 163 pCAP310 RLRCLLLLIGRVGRR 4 4 90 pCAP311 EIHTIHLLPERR 0 149 pCAP312 RRPRIPDYIL 3 3 223 pCAP313 my r-RRREILHPEFRILYE 2 6 8 150 pCAP314 RSTPHIHEFI RR 3 3 229 pCAP315 LHFSHIDRR 3 6 9 210 pCAP316 my r-DIHTIHLPDTHRR 3 4 7 309 pCAP317 RRDIHTIHPFYQ HSD17 5 4 3 4 2 5 1 6 5 5 3 43 204 pCAP318 RPEFHSFHPIYERR 3 3 6 151 pCAP319 SHDFYPHWMRERIR 3 3 91 pCAP320 EPSHPRSRYPRTF 0 92 pCAP321 RNIIIRDFIHFSHIDR 0 93 pCAP322 RRIRDPQIK-myrLEIHFSHID 0 94 pCAP323 my r-DLHTIHI PRDRR 0 95 pCAP324 SHDFPHREPRPERR 0 317 pCAP325 my r-RRIRDPRILLLHFD CCT3 4 6 3 4 3 6 6 4 3 4 5 4 3 6 61 313 pCAP326 my r-RRHNAHHSTPHPDDR RAD9A 3 6 3 3 4 6 4 4 6 4 6 4 53 *AS - Activity Score.

TABLE 9 Experiment number 2 3 4 Cell line type MDA-MB-231 SW-480 SKBR3 P53^(R280H) p53^(R273H,P309S) p53^(R175H) Group Control Treatment Control Treatment 325 Control Treatment pCAPs pCAPs pCAPs pCAPs pCAP pCAPs pCAPs Number of 12 18 10 10 10 10 10 samples IVIS average 209% 1.1% 275.4% 3.3% 4.4% 1000% 43.7% ratio to day 0 Number of 0 10 0 4 2 0 0 total regression Samples 1.26 0.27 0.87 0.15 0.12 0.38 0.15 average size Samples 1.11 0.29 0.53 0.15 0.10 0.53 0.24 average weight

TABLE 10 SEQ ID Activity NO: Plasmid Sequence Score 17 pCAP8 LTFEHYWAQLTS 0 18 pCAP12 GGGGGGGGGGGG 0 19 pCAP19 NPNTYVPHWMRQ 0 20 pCAP25 YRRLLIGMMW 0 21 pCAP26 DEFHSFYTARQTG 0 22 pCAP29 KPDSPRV 0 23 pCAP31 PPYSQFLQWYLS 0 24 pCAP40 SEFPRSWDMETN 0 25 pCAP45 HDTHNAHVG 0 26 pCAP50 WSEYDIPTPQIPP 0 27 pCAP69 SILTLSRRRRRRRRRR 0 28 pCAP73 SCRCRLRGDRGDR 0 29 pCAP76 GGGGGGGGGRRRRRRR 0 30 pCAP77 SEYLCSSLDAAG 0 31 pCAP78 GESFVQHVFRQN 0 32 pCAP79 SVHHHHRMHLVA 0 33 pCAP84 GRRRFCM 0 34 pCAP85 KLTIHHH 0 35 pCAP86 FGSHHEL 0 36 pCAP96 GTVDHHA 0 37 pCAP107 DRLSVFLFIM 0 38 pCAP114 AISHHTR 0 39 pCAP116 KHHPFDHRLGNQ 0 40 pCAP119 HSAHHTM 0 41 pCAP125 ELGLHRH 0 42 pCAP126 RRLRICV 0 43 pCAP156 VPHIHEFTRRRRRRRR 0 44 pCAP164 PLTLI 0 45 pCAP165 SLLIG 0 46 pCAP166 KPPER 0 47 pCAP168 CRIIR 0 48 pCAP169 SFILI 0 49 pCAP171 PHHHS 0 50 pCAP172 EFHS 0 51 pCAP173 RLRRL 0 52 pCAP175 DSPR 0 53 pCAP176 HPWTH 0 54 pCAP177 HFSHH 0 55 pCAP178 RRVI 0 56 pCAP179 ILVI 0 57 pCAP207 RRSRSNEDVEDKTEDE 0 58 pCAP208 RRIRSGGKDHAWTPLHENH 0 59 pCAP209 HTPHPPVARTSPLQTPRR 0 60 pCAP211 PDSEPPRMELRRR 0 61 pCAP215 RRDTFDIRILMAF 0 62 pCAP218 RREVTELHHTHEDRR 0 63 pCAP223 SPWTHERRCRQR 0 64 pCAP232 RSRSSHLRDHERTHT 0 65 pCAP236 RRRSTNTFLGEDFDQ 0 66 pCAP241 LIGLSTSPRPRIIR 0 67 pCAP248 EIYGESGKTDEHALDTEYRR 0 68 pCAP252 RRVILRSYDGGHSTPHPD 0 69 pCAP253 TGKTFVKRHLTEFEKKYR 0 70 pCAP254 NHFDYDTIELDTAGEYSRRR 0 71 pCAP255 DPEPPRYLPPPPERR 0 72 pCAP260 RRTFIRHRIDSTEVIYQDED 0 73 pCAP262 ESKTGHKSEEQRLRRYR 0 74 pCAP263 YDDEHNHHPHHSTHRRR 0 75 pCAP264 RRRREVHTIHQHGIVHSD 0 76 pCAP269 DEPLPPPERRR 0 77 pCAP270 SPHPPY 0 78 pCAP271 SPHPPYSPHPPYSPHPPYP 0 79 pCAP272 RRPHNLHHD 0 80 pCAP274 LRDPHPPERRIR 0 81 pCAP283 RRPADQISYLHPPER 0 82 pCAP291 DLQYDFPRIRR 0 83 pCAP292 YDELYQKEDPHRRR 0 84 pCAP294 FKPERFPQNDRRR 0 85 pCAP296 RPADRIRR 0 86 pCAP297 HDFDPRYRDRR 0 87 pCAP300 RIRRDPDSPLPHPE 0 88 pCAP304 myr-RRIRILMFLIGCGRV 0 89 pCAP309 HPHVILPRIRIRIR 0 90 pCAP311 EIHTIHLLPERR 0 91 pCAP320 EPSHPRSRYPRTF 0 92 pCAP321 RNIIIRDFIHFSHIDR 0 93 pCAP322 RRIRDPQIK-myrLEIHFSHID 0 94 pCAP323 myr-DLHTIHIPRDRR 0 95 pCAP324 SHDFPHREPRPERR 0 96 pCAP219 SYRHYSDHWEDRRR 1 97 pCAP2 VWVHDSCHANLQNYRNYLLP 2 98 pCAP4 EHDFEVRGDVVNGRNHQGPK 2 99 pCAP5 LEVIYMI 2 100 pCAP38 WTLSNYL 2 101 pCAP39 DSLHSTY 2 102 pCAP41 WHHRQQIPRPLE 2 103 pCAP64 APSIFTPHAWRQ 2 104 pCAP66 THFSHHLKGGGRRQRRRP 2 105 pCAP67 LHSKTLVLGGGRRRRGDR 2 106 pCAP71 WTLSNYLGGRKKRRQRRRR 2 107 pCAP81 VRCIFRGIWVRL 2 108 pCAP98 HSSGHNFVLVRQ 2 109 pCAP110 LFILVFR 2 110 pCAP112 TTSHHPK 2 111 pCAP124 VMVLFRILRGSM 2 112 pCAP162 SILT 2 113 pCAP214 RRRESEQRSISLHHHST 2 114 pCAP216 myr-HFNHYTFESTCRRRRC 2 115 pCAP217 HSTPHPPQPPERRR 2 116 pCAP224 RRKSEPHSLSGGYQTGAD 2 117 pCAP234 HRTGHYTRCRQRCRSRSHNRH 2 118 pCAP243 RRCRSILPLLLLSR 2 119 pCAP256 RTLHGRRVILHEGGHSISDLK 2 120 pCAP266 HHRLSYFIVRRHSTHASR 2 121 pCAP293 RRIRIDPQHD 2 122 pCAP299 ILQPDFLIRPE 2 123 pCAP307 HDPRIIRIR 2 124 pCAP52 SPYPIRT 3 125 pCAP53 ILVIIQRIM 3 126 pCAP101 IRFILIR 3 127 pCAP102 SSVHHRG 3 128 pCAP103 LRRQLQL 3 129 pCAP113 HTTAHTH 3 130 pCAP115 HPHNHTVHNVVY 3 131 pCAP117 DHSKFVPLFVRQ 3 132 pCAP120 SIRTLGRFLIIRV 3 133 pCAP123 GLCRIIL 3 134 pCAP127 SPPIRHH 3 135 pCAP201 HPTHPIRLRDNLTR 3 136 pCAP212 myr-REEETILIIRRR 3 137 pCAP225 HTIHSISDFPEPPDRRRR 3 138 pCAP228 DEDAAHSTGHPHNSQHRRRR 3 139 pCAP240 TEQHHYIPHRRR 3 140 pCAP251 RLRRVILRSYHE 3 141 pCAP265 EEPDRQPSGKRGGRKRRSR 3 142 pCAP273 RDFHTIHPSISRR 3 143 pCAP276 RRVDIHDGQRR 3 144 pCAP277 DQPYPHRRIR 3 145 pCAP281 myr-RDFILFIRRLGRR 3 146 pCAP295 LDLYHPRERR 3 147 pCAP298 RRIRDPLGNEHE 3 148 pCAP303 IVEFRIRR 3 149 pCAP312 RRPRIPDYIL 3 150 pCAP314 RSTPHIHEFIRR 3 151 pCAP319 SHDFYPHWMRERIR 3 152 pCAP13 HFSHHLK 4 153 pCAP32 TSPLQSLK 4 154 pCAP51 AILTLILRRVIWP 4 155 pCAP94 LRFIDYP 4 156 pCAP109 GPIKHHLQHH 4 157 pCAP163 LTLS 4 158 pCAP222 RYEENNGVNPPVQVFESRTR 4 159 pCAP239 REGFYGPWHEQRRR 4 160 pCAP285 RRDIIRHNAHS 4 161 pCAP286 HDFHDYLERR 4 162 pCAP305 IREFDPRRIR 4 163 pCAP310 RLRCLLLLIGRVGRR 4 164 pCAP6 LGIDEDEETETAPE 5 165 pCAP22 SLLIGFGIIRSR 5 166 pCAP27 VHEVTHHWL 5 167 pCAP56 ATPFHQT 5 168 pCAP58 SILPLFLIRRSG 5 169 pCAP72 SCRCRLRRRRRRRRRR 5 170 pCAP105 SRIVLGW 5 171 pCAP111 SNIHHQV 5 172 pCAP121 LTLMRLRIIG 5 173 pCAP122 HSYSPYYTFRQH 5 174 pCAP167 FILIR 5 175 pCAP205 RCRNRKKEKTECLQKESEK 5 176 pCAP213 RRIKMIRTSESFIQHIVS 5 177 pCAP244 RRVSELQRNKHGRKHEL 5 178 pCAP246 RRRLDDEDVQTPTPSEYQN 5 179 pCAP261 RRRQPLPSAPENEE 5 180 pCAP7 SPLQTPAAPGAAAGPALSPV 6 181 pCAP18 SHQVHTHHNN 6 182 pCAP37 KLQVPIK 6 183 pCAP74 IRGRIIRRKKRRQRRRRGDR 6 184 pCAP82 QIPHRSSTALQL 6 185 pCAP88 SYQTMQP 6 186 pCAP140 TDSHSHHRRRRRRRRRRR 6 187 pCAP143 IPMNFTSHSLRQRRRRRRRRR 6 188 pCAP153 YWSAPQPATRRRRRRRRRRR 6 189 pCAP220 STTHPHPGTSAPEPATRRR 6 190 pCAP226 DDSDNRIIRYRR 6 191 pCAP238 TSPHPSLPRHIYPRR 6 192 pCAP247 RRITEIRGRTGKTTLTYIED 6 193 pCAP249 myr-DERTGKTRRYIDTRDIRR 6 194 pCAP275 myr-MTYSDMPRRIITDEDRRR 6 195 pCAP278 RRYDTVIDDIEYRR 6 196 pCAP279 RDTIERPEIRR 6 197 pCAP280 myr-RYRRLILEIWRR 6 198 pCAP284 myr-RHDTHNAHIRR 6 199 pCAP288 THDFDRLLRIRRR 6 200 pCAP289 RHNHIRPDNQ 6 201 pCAP290 RYKEPRITPRE 6 202 pCAP302 LRIEPIRIR 6 203 pCAP306 myr-RLIRMILM 6 204 pCAP318 RPEFHSFHPIYERR 6 205 pCAP91 STTHIHA 7 206 pCAP92 FPHLVSSLTT 7 207 pCAP99 GLHLFTTDRQGW 7 208 pCAP132 NHPWQFPNRWTRRRRRR 7 209 pCAP145 HSSHHHPVHSWNRRRRRRR 7 210 pCAP316 myr-DIHTIHLPDTHRR 7 211 pCAP10 VAEFAQSIQSRIVEWKERLD 8 212 pCAP49 TRILCIVMM 8 213 pCAP55 FLLPEPDENTRW 8 214 pCAP57 LMSNAQY 8 215 pCAP89 SILTLSCRCRLRLWR 8 216 pCAP95 HQIHRNHTY 8 217 pCAP106 LIRRCSLQR 8 218 pCAP137 GAMHLPWHMGTRRRRRR 8 219 pCAP202 DEDAKFRIRILMRR 8 220 pCAP245 NHITNGGEEDSDCSSRRRRL 8 221 pCAP257 myr-HSSHHHPTVQHRR 8 222 pCAP287 RDFERTIVDI 8 223 pCAP313 myr-RRREILHPEFRILYE 8 224 pCAP14 HHFSHHWKT 9 225 pCAP59 FLIRRSG 9 226 pCAP63 HNHHHSQHTPQH 9 227 pCAP80 HLHKHHYKDSRM 9 228 pCAP231 HRTQSTLILFIRRGRET 9 229 pCAP315 LHFSHIDRR 9 230 pCAP62 YELPHHAYPA 10 231 pCAP133 SLLIGFGIIRSRRRRRRRR 10 232 pCAP135 HTDSHPHHHHPHRRRRR 10 233 pCAP147 ATQHHYIKRRRRRRRRRRR 10 234 pCAP129 FRSFAIPLVVPFRRRRRRR 11 235 pCAP138 YPTQGHLRRRRRRRRRRRR 11 236 pCAP146 HANLHHTRRRRRRRRRRR 11 237 pCAP152 YRRLLIGMRRRRRRRRRRRR 11 238 pCAP233 SHYHTPQNPPSTRRR 11 239 pCAP235 RSYSKLLCLLERLRISP 11 240 pCAP3 FWTQSIKERKMLNEHDFEVR 12 241 pCAP15 THFSHHLKH 12 242 pCAP90 SCRCRLR 12 243 pCAP139 MHPPDWYHHTPKRRRRRR 12 244 pCAP237 HTIHVHYPGNRQPNPPLILQR 12 245 pCAP268 TPSYGHTPSHHRRR 12 246 pCAP301 myr-IRGRIRIIRR1R 12 247 pCAP20 HHPWTHHQRWS 13 248 pCAP48 IPMNFTSHSLRQ 13 249 pCAP118 SNHHHRHHTNTH 13 250 pCAP130 EVTFRHSVVRRRRRRRRRRR 13 251 pCAP149 FPGHTIHRRRRRRRRRRR 13 252 pCAP34 SILTLSRIVLGWW 14 253 pCAP47 TLYLPHWHRH 14 254 pCAP136 SILTLRLRRLRRRRRRRR 14 255 pCAP142 TLYLPHWHRHRRRRRRRRRR 14 256 pCAP43 TDSHSHH 15 257 pCAP11 EWKERLDKEFSLSVYQKMKF 16 258 pCAP30 TIHPSIS 16 259 pCAP33 SILTLRLRRLRR 16 260 pCAP44 VPHIHEFT 16 261 pCAP9 TIIHREDEDEIEW 17 262 pCAP61 KDLPFYSHLSRQ 17 263 pCAP65 THFSHHLKHRRRRRRRRRR 17 264 pCAP93 ATQHHYIK 17 265 pCAP108 IIRGNFLIGGRL 17 266 pCAP131 LPNPPERHHRRRRRRRRRRR 18 267 pCAP158 SFILFIRRGRLGRGDR 18 268 pCAP100 FPGHTIH 19 269 pCAP128 CILRLWW 19 270 pCAP206 RRRSHSQENVDQDTDE 19 271 pCAP204 MSTESNMPRLIQNDDRRR 20 272 pCAP104 LLRLGLI 21 273 pCAP23 IRILMFLIGCGR 22 274 pCAP17 LHSKTLVL 23 275 pCAP24 LRCLLLLIGRVG 23 276 pCAP258 FLIGPDRLIRSR 23 277 pCAP16 LPNPPERHH 24 278 pCAP28 HTDSHPHHHHPH 24 279 pCAP160 Fitc-SFILFIRRGRLGRRRRRRRRR 24 280 pCAP83 HSSHHHPVHSWN 25 281 pCAP259 myr-RTLIGIIRSHHLTLIRR 25 282 pCAP54 IRGRIIR 26 283 pCAP150 IIRGNFLIGGRLRRRRRRRRR 26 284 pCAP170 IRILM 27 285 pCAP35 GAMHLPWHMGTL 28 286 pCAP267 KRGGRKRRGGGHRLSYFIRR 28 287 pCAP21 NHPWQFPNRWTV 29 288 pCAP42 MHPPDWYHHTPKH 29 289 pCAP141 SWQALALYAAGWRRRRRR 29 290 pCAP161 HNAH 29 291 pCAP210 DEFERYRRFSTSRRR 29 292 pCAP1 EVTFRHSVV 32 293 pCAP75 TRILCIVRKKRRQRRRRGDR 32 294 pCAP70 SILTLSRGRKKRRQRRRR 33 295 pCAP151 CILRLWWRRRRRRRRRRR 33 296 pCAP46 ASWQALALYAAGW 34 297 pCAP229 myr-PRVLPSPHTIHPSQYP 36 298 pCAP87 HANLHHT 37 299 pCAP157 SFILFIRRGRLGRKKRRQRRRP 37 300 pCAP36 YPTQGHLR 39 301 pCAP68 YRRLLIGMMWRRRRRRRRRRR 39 302 pCAP60 SFILFIRRGRLG 40 303 pCAP134 IRILMFLIGCGRRRRRRRR 40 304 pCAP308 myr-RRICRFIRICRVR 40 305 pCAP155 IRGRIIRRRRRRRRRR 41 306 pCAP203 RRRHDSCHNQLQNYDHSTE 42 307 pCAP148 WNHHHSTPHPRRRRRRRRRR 43 308 pCAP282 myr-RRPVAPDLRHTIHIPPER 43 309 pCAP317 RRDIHTIHPFYQ 43 310 pCAP97 WNHHHSTPHPAH 47 311 pCAP144 SFILFIRRGRLGRRRRRRRRR 49 312 pCAP159 rrrrrrrrglrgrriflifs 53 313 pCAP326 myr-RRHNAHHSTPHPDDR 53 314 pCAP174 HSTPHP 54 315 pCAP154 LRCLLLLIGRVGRKKRRQRR 57 316 pCAP221 myr-RRKHNKHRPEPDSDER 60 317 pCAP325 myr-RRIRDPRILLLHFD 61 318 pCAP230 RKRGKSYAFFVPPSESKERW 63 319 pCAP227 myr-RRKILFIRLMHNKH 67 320 pCAP242 myr-RRLIVRILKLPNPPER 67 321 pCAP250 myr-RRHSTPHPD 72

The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.

All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is/are hereby incorporated herein by reference in its/their entirety. 

What is claimed is:
 1. A recombinant or synthetic peptide comprising the amino-acid sequence selected from the group consisting of SEQ ID NO: 139, 140, 203, 216 and 227, wherein said peptide at least partially reactivates a mutant p53 protein; and wherein said peptide is up to 15 amino-acids in length.
 2. The peptide of claim 1, conjugated to at least one cell permeation moiety.
 3. The peptide of claim 1, wherein said peptide at least partially changes the conformation of said mutant p53 protein to a conformation of a wild-type (WT) p53 protein.
 4. The peptide of claim 1, wherein said peptide at least partially changes the conformation of said mutant p53 protein such that said mutant p53 protein is recognized by a monoclonal antibody directed against a WT p53 protein.
 5. The peptide of claim 1, wherein said mutant p53 protein is not recognized by a monoclonal antibody directed against a WT p53 protein.
 6. The peptide of claim 1, wherein said mutant p53 protein, upon binding to said peptide, is recognized by an antibody directed against a WT p53 protein.
 7. The peptide of claim 6, wherein said antibody is Ab1620.
 8. The peptide of claim 1, wherein said peptide at least partially restores the activity of said mutant p53 protein to the activity of a WT p53 protein.
 9. The peptide of claim 8, wherein said activity is reducing viability of cells expressing said mutant p53 protein.
 10. The peptide of claim 8, wherein said activity is promoting apoptosis of cells expressing said mutant p53 protein.
 11. The peptide of claim 8, wherein said activity is binding to a p53 consensus DNA binding element in cells expressing said mutant p53 protein.
 12. The peptide of claim 11, wherein said binding results in at least partial activation of an endogenous p53 target gene.
 13. The peptide of claim 12, wherein said endogenous target gene is selected from the group consisting of p21, MDM2 and PUMA.
 14. The peptide of claim 1, wherein said mutant p53 protein is of a different conformation than a WT p53 protein.
 15. The peptide of claim 1, wherein said mutant p53 protein is at least partly inactive compared to a WT p53 protein.
 16. The peptide of claim 1 attached to a cell penetrating moiety.
 17. A recombinant or synthetic peptide comprising the amino-acid sequence set forth in any one of SEQ ID NOs: 139, 140, 203, 216 and 227, wherein said peptide is up to 15 amino-acids in length.
 18. A method of treating a disorder associated with mutant p53 protein, lessening a severity of a disease associated with a mutant p53 protein or ameliorating symptoms associated with a disease associated with a mutant p53, comprising the step of administering a therapeutically effective amount of the peptide of claim 1 to a subject in need thereof, thereby treating said disorder associated with mutant p53 protein, lessening the severity of said disease associated with a mutant p53 protein or ameliorating symptoms associated with said disease associated with said mutant p53.
 19. The method of claim 18, wherein said disease is cancer.
 20. A method of treating a disorder associated with mutant p53 protein, lessening a severity of a disease associated with a mutant p53 protein or ameliorating symptoms associated with a disease associated with a mutant p53, comprising the step of administering a therapeutically effective amount of the peptide of claim 16 to a subject in need thereof, thereby treating said disorder associated with mutant p53 protein, lessening the severity of said disease associated with a mutant p53 protein or ameliorating symptoms associated with said disease associated with said mutant p53.
 21. A recombinant or synthetic peptide comprising the amino-acid sequence set forth in any one of SEQ ID NOs: 244 and 263, wherein said peptide is up to 30 amino-acids in length.
 22. A method of treating a disorder associated with mutant p53 protein, lessening a severity of a disease associated with a mutant p53 protein or ameliorating symptoms associated with a disease associated with a mutant p53, comprising the step of administering a therapeutically effective amount of the peptide of claim 17 to a subject in need thereof, thereby treating said disorder associated with mutant p53 protein, lessening the severity of said disease associated with a mutant p53 protein or ameliorating symptoms associated with said disease associated with said mutant p53.
 23. The method of claim 22, wherein said disease is cancer. 